Service Training Meeting Guide 672
SESV1672-01 April 1997
TECHNICAL PRESENTATION
3408E/3412E HEUI FUEL SYSTEM TO LUBE SYSTEM HEUI HYDRAULIC TEMPERATURE SENSOR
COLD START OIL RESERVOIR
OIL FILTER
COOL DOWN CIRCUIT
HYDRAULIC SUPPLY PUMP GROUP
OIL COOLER
FLUID MANIFOLD HYDRAULIC PASSAGE
OIL PRESSURE SENSOR
HYDRAULIC PRESSURE SENSOR
FUEL TEMPERATURE SENSOR
FLUID MANIFOLD HYDRAULIC PASSAGE
PUMP CONTROL VALVE FUEL TRANSFER PUMP
LUBE OIL PUMP
PRIMARY FUEL FILTER WATER SEPARATOR OIL SUMP
HEUI
ECM
SECONDARY FUEL FILTER
PRESSURE REGULATING VALVE
FUEL TANK
3408E/3412E ENGINE CONTROLS HYDRAULIC ELECTRONIC UNIT INJECTION (HEUI)
3408E/3412E ENGINE CONTROLS HYDRAULIC ELECTRONIC UNIT INJECTION (HEUI) MEETING GUIDE 672 SLIDES AND SCRIPT AUDIENCE Level II - Service personnel who understand the principles of engine systems operation, diagnostic equipment, and procedures for testing and adjusting.
CONTENT This presentation is designed to prepare a service technician to identify the components, explain their function, and service the 3408E/3412E Hydraulic Electronic Unit Injection (HEUI) engines in all current machine and industrial applications.
OBJECTIVES After learning the information in this presentation, the serviceman will be able to: 1. locate and identify the major components in the 3400 HEUI system; 2. explain the functions of the major components in the 3400 HEUI system; 3. trace the flow of oil through the engine hydraulic system; 4. trace the flow of fuel through the fuel system; and 5. trace the flow of current through the engine electrical system.
PREREQUISITES Interactive Video Course "Fundamentals of Mobile Hydraulics" Interactive Video Course "Fundamentals of Electrical Systems" Programmed Instruction Course "Basic Electricity" STMG 546 "Graphic Fluid Power Symbols"
TEVR9001 TEVR9002 SEBV0534 SESV1546
Prior training in systems operation and testing and adjusting procedures for the 3408C/3412C engines should be completed before participating in this training session. Additionally, the participants should have PC skills and have completed introductory training in Windows® software.
Estimated Time: 8 Hours Visuals: 138 (2 X 2) Slides Serviceman Handouts: 8 Drawings/Data Sheet Form: SESV1672-01 Date: 4/97 © 1997 Caterpillar Inc.
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SUPPLEMENTARY TRAINING MATERIAL Video Tape "3408E/3412E HEUI Service Introduction" Brochure "Caterpillar 3408E and 3412E Engines" ESTMG "Introduction to Electronic Technician" Brochure "Caterpillar Electronic Technician" Wall Chart "HEUI Fuel System" (small) Wall Chart "HEUI Fuel System" (large) Wall Chart "HEUI Engine"
SEVN3550 LEDH6055 LEPV5155 NEHP5614 LEWH6116 LEWH6266 LEWH6740
Training Book "Easy Windows, 3.1 Edition" by Shelly O'Hara Available from: Prentice Hall Computer Publishing 0-88022-985-3 Attn: Order Dept. 201 W. 103rd St. Indianapolis, IN 46290 Reference Book "Field Guide to Microsoft Windows 95" by Stephen L. Nelson Available from: Microsoft Press International at Fax No. (206) 936-7329 Also available from bookstores Training Book "Windows 95 for Dummies" Published by IDG Books IDG Books World Wide Website: http://www.idgbooks.com Available from bookstores
RECOMMENDED HEUI TOOLING Caterpillar Electronic Technician Single Use License Caterpillar Electronic Technician Annual Data Subscription (All Engines and Machines)
JERD2124 JERD2129
Communication Adaptor PC to Communication Adaptor Cable Communication Adaptor to Machine Cable (combined ATA and CDL Data Link cable; replaces 7X1570 and 7X1412) Digital Multimeter (Fluke 87) Cable Probes
7X1700 7X1425 139-4166
Hydraulic Unit Injector Puller Hydraulic Unit Injector Sleeve Removal Wrench
131-3921 111-5051
9U7330 7X1710
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REFERENCES Troubleshooting Manual "3408E Engine--631E - 637E Wheel Tractor-Scrapers" Troubleshooting Manual "3412E Engine--24H Motor Grader" Troubleshooting Manual "3408E Engine--834B/836 Wheel Tractors" Troubleshooting Manual "3408E/3412E Engines--D9R/D10R Track-type Tractors" Troubleshooting Manual "3408E/3412E Engines--988F/990 Wheel Loaders" Troubleshooting Manual "3408E/3412E Engines--769D - 775D Off-highway Trucks" Troubleshooting Manual "3408E/3412E Engines--Industrial Applications" Troubleshooting Manual "3408E/3412E Engines--651E - 657E Wheel Tractor-Scrapers"
SENR1037 SENR1038 SENR1052 SENR1054 SENR1060 SENR1062 SENR1065 SENR1076
Disassembly and Assembly Manual "3408E/3412E Captive Engines" Disassembly and Assembly Manual "3408E/3412E Industrial and Marine Engines"
SENR1013 SENR1063
Testing and Adjusting Manual "3408E/3412E Engines--Captive Engines" Testing and Adjusting Manual "3408E/3412E Engines--Industrial Engines"
SENR1018 SENR1033
Electrical Schematic "3408E/3412E Captive Engines" Electrical Schematic "3408E/3412E Industrial Engines"
SENR1026 SENR1064
Special Instruction "Using the ECAP" Special Instruction "Installing the 7X1180 ECAP Expansion Board"
SEHS8742 SEHS8833
Tool Operating Manual "Using the Communication Adapter" Tool Operating Manual "Using the Machine Functions Service Program Module"
SEHS9264 SEHS9343
Parts Manual "3408E Industrial Engine"
SEBP2509
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TABLA DE CONTENIDOS INTRODUCCION..................................................................................................................7 Vista Genreal ..........................................................................................................................8 Compoentes Principales ...........................................................................................................9 SISTEMA DE CONTROL ELECTRONICO .......... ............................................................26 Fuel Injection .................................................................................................................29 Fuel Injection Control System .......................................................................................31 FUEL INJECTION SYSTEM .............................................................................................49 System Components .......................................................................................................51 System Operation ...........................................................................................................53 Hydraulic Unit Injector Operation .................................................................................56 Injector Operation Characteristics ..................................................................................61 Injector Components ......................................................................................................64 Injector Removal and Installation ..................................................................................68 Injection Sequence .........................................................................................................71 HYDRAULIC SYSTEM......................................................................................................82 Hydraulic Supply Pump Group ......................................................................................83 System Operation ...........................................................................................................93 SYSTEM POWER SUPPLIES ..........................................................................................105 ECM Power Supply .....................................................................................................106 Speed/Timing Sensor Power Supply ............................................................................108 Injector Power Supplies ..............................................................................................109 Analog Sensor Power Supply ......................................................................................110 Digital Sensor Power Supply .......................................................................................111 Pump Control Valve Power Supply .............................................................................112 ELECTRONIC SENSORS AND SYSTEMS ....................................................................114 Speed/Timing Sensors ..................................................................................................115 Analog Sensors and Circuits ........................................................................................117 Digital Sensors and Circuits .........................................................................................131 Engine Shutdown Systems ...........................................................................................135 Demand Fan Controls ..................................................................................................137 Ether Injection System .................................................................................................138 CAT Data Link .............................................................................................................139 Logged Events ..............................................................................................................141 MACHINE APPLICATIONS ............................................................................................144 D9R/D10R Track-type Tractors ...................................................................................145 988F/990 Series II Wheel Loaders ..............................................................................149 769C/771C/773B/775B Off-highway Trucks ..............................................................152 3408E/3412E HEUI Industrial Engines .......................................................................155 SLIDE LIST .......................................................................................................................158 SERVICEMAN'S HANDOUTS ........................................................................................160
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INSTRUCTOR NOTES
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3408E/3412E ENGINE CONTROLS HYDRAULIC ELECTRONIC UNIT INJECTION (HEUI)
©1997 Caterpillar Inc.
1 INTRODUCTION • Major topics
This presentation discusses the 3408E/3412E Hydraulic Electronic Unit Injection (HEUI) Engine Controls in all applications. The topics are sequenced as follows: - Introduction and Major Components - Electronic Control System - Fuel Injection System - Hydraulic System - System Power Supplies - Electronic Sensors and Systems - Machine Applications INSTRUCTOR NOTE: This presentation refers to and describes Electronic Technician (ET) as the programming tool for the 3408E/3412E engines. As new and more sophisticated electronic engine controls are now in use, the Electronic Control Analyzer Programmer (ECAP) is no longer adequate for all tasks (such as flash programming). The ET software, installed on a PC, is now the principle tool used in programming.
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2 Overview The 3408E/3412E engines equipped with the HEUI fuel system are available in construction equipment and industrial applications. Industrial engines are available in both 3408C/3412C (pump and line fuel system) and 3408E/3412E HEUI versions. Caterpillar machines powered by the 3408E/3412E engines which feature HEUI include: • HEUI applications
- 769D/771D/773D Off-highway Trucks - 988F/990 Series II Wheel Loaders - D9R/D10R Track-type Tractors - 631E/637E/651E/657E Wheel Tractor-Scrapers - 24H Motor Grader
• System features
The HEUI engines have many features and benefits not possible with mechanical fuel systems. These features include a very clean exhaust, improved fuel consumption and cold starting, simplified maintenance with fewer moving parts, and reduced operating costs. The system has additional advantages which will be covered later in this presentation.
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3408E/3412E HEUI FUEL SYSTEM TO LUBE SYSTEM HEUI HYDRAULIC TEMPERATURE SENSOR
COLD START OIL RESERVOIR
OIL FILTER
COOL DOWN CIRCUIT
HYDRAULIC SUPPLY PUMP GROUP
OIL COOLER
FLUID MANIFOLD HYDRAULIC PASSAGE
OIL PRESSURE SENSOR
SENSOR DE PRESION HIDRAULICA
FUEL TEMPERATURE SENSOR
FLUID MANIFOLD HYDRAULIC PASSAGE
PUMP CONTROL VALVE FUEL TRANSFER PUMP
LUBE OIL PUMP
PRIMARY FUEL FILTER WATER SEPARATOR SUMINDERO DE ACEITE
ECM
HEUI
FILTRO SECUNDARIO DE COMBUSTIBLE
VALVULA REGULADORA DE PRESION
TANQUE DE COMBUSTIBLE
3 Major Components This schematic shows the various components in the HEUI fuel system. A detailed explanation of the system and the various components follows later in this presentation. • Electronically similar to EUI system
The electronic components in the HEUI fuel system are very similar to those used in other EUI systems. However, in the HEUI system, the injectors are not actuated by a camshaft.
• Hydraulic pump raises pressure
A high pressure hydraulic pump, which draws oil from the pressure side of the lubrication pump, raises the pressure to a maximum of 22800 kPa (3300 psi). The pressure is controlled by the Electronic Control Module (ECM). The hydraulic flow is directed to hydraulic actuators in each injector.
• Hydraulic pressure controlled by ECM
• Injectors electronically signalled
The injectors are electronically signalled (as in the EUI system) to permit oil under high pressure to move a piston which then moves the fuel plunger.
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1
2
3
7
6
5
4
4 • Siete tipos de componentes principales 1. Hydraulic supply pump group 2. ECM
This slide shows seven of the major types of components in the HEUI fuel system. • Hydraulic Supply Pump Group (1) containing: - High pressure hydraulic pump - Pump control valve
3. Throttle control
- Transfer pump
4. Speed/timing sensor
• ECM (2)
5. Injector
• Throttle Control (3)
6. Temperature sensor
• Speed/Timing Sensor (4)
7. Pressure sensor
• Injector (5) • Temperature Sensor (6)
• CAT Data Link and coolant flow switch (not shown)
• Pressure Sensor (7) The CAT Data Link (not shown) provides a two-way communication path between the HEUI system and the remaining electronic circuits or systems on the machine. The CAT Data Link also allows the service tool to communicate with the engine electronic system. NOTE: Only one example of each sensor (pressure, temperature and speed/timing) is shown on the slide.
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2 222
1
5 • 3400 HEUI engine top view
1. ECM--the "heart" of the system
• Personality module access panel located below ECM
2. Hydraulic supply pump group
• Wiring harness
The principal component in the HEUI system, the Electronic Control Module (1), is mounted on top of the right front valve cover. The ECM is the "heart" of the engine. The ECM performs engine governing, timing and fuel limiting. It also reads sensors and communicates to the instrument display system through the CAT Data Link. The Personality Module is used to program the ECM with all the rating information for a particular application. The Personality Module can be changed by direct replacement or can be flash programmed (reprogrammed) using a PC. The Personality Module Access Panel is located below the ECM. The Hydraulic Supply Pump Group (2) is mounted in the vee of the engine in the same position as the original fuel pump and governor for the 3408C/3412C engines. Flow from this pump supplies the actuating pressure for the injectors. Mounted on the rear of the pump is the fuel transfer pump. Among the visible components are the Wiring Harness and 40 Pin Connectors to the ECM. INSTRUCTOR NOTE: The slides which follow show machine and industrial engines. The physical appearance and function of the HEUI machine and industrial engine components are very similar.
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5
3 1
2
6
4
6 • Engine upper left side view 1. Fuel temperature sensor 2. Atmospheric pressure sensor 3. Lubrication oil pressure sensor 4. Hydraulic temperature sensor 5. Machine interface connector 6. Ground bolt
This view from the upper left side of the engine shows the Fuel Temperature Sensor (1). The Atmospheric Pressure Sensor (2) is mounted on the Hydraulic Supply Pump Group mounting adapter. Mounted on the Hydraulic Supply Pump Group is the Lubrication Oil Pressure Sensor (3). The sensor is used by the ECM to generate a low oil pressure warning for the operator. Also mounted on the Hydraulic Supply Pump Group is thelUBRICATION Temperature Sensor (4). This sensor is used by the ECM for viscosity compensation to maintain consistent fuel delivery and injector timing regardless of viscosity changes caused by varying hydraulic temperatures. Both sensors are threaded into the supply pump case. The 40 Pin Machine Interface Connector (5) is mounted behind the Hydraulic Supply Pump Group. This component makes the connection between the engine and machine wiring harnesses. A vital part of the wiring assembly is the Ground Bolt (6) mounted on the machine interface connector bracket. NOTE: Oil flow from the Hydraulic Supply Pump Group will be referred to as "hydraulic" to avoid confusion with the lubrication system.
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1
3
2
7 1. Timing calibration connector
The Timing Calibration Connector (1) is located adjacent to the ECM.
2. Hydraulic pressure sensor
The Hydraulic (Injection Actuation) Pressure Sensor (2) is located between the valve cover bases in the right Fluid Supply Manifold.
3. Injector connector
The Injector Connector (3) is one of four connectors on a 3408E. (Each connector supplies current to two injector solenoids.)
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8 • Coolant temperature sensor (arrow)
The engine Coolant Temperature Sensor (arrow) is located in the front of the right cylinder head. This sensor is used with the ECM to control various functions. The following systems or circuits use the Temperature Sensor output to the ECM: The Vital Information Management System (VIMS) or Caterpillar Monitoring System Coolant Temperature Gauge over the CAT Data Link. The High Coolant Temperature Warning Alert Indicator LED and Gauge on the VIMS or Caterpillar Monitoring System panel. (The information is transmitted over the CAT Data Link.) The Engine Demand Fan Control, if installed, uses the sensor signal reference to provide the appropriate fan speed. The Cat Electronic Technician (ET) status screen coolant temperature indication.
• Coolant flow switch (not visible)
The Coolant Flow Switch (not visible in this view) is mounted below the coolant temperature sensor at the inlet to the oil cooler.
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9 • Secondary speed/timing sensor (arrow)
This view shows one of the Speed/Timing Sensors (arrow). A sensor is mounted on each side of the timing gear housing. This slide shows the secondary Speed/Timing Sensor. The primary Speed/Timing Sensor is located closest to the ECM. These sensors are used to calculate engine speed and crankshaft position for timing purposes. The sensors are self-adjusting, but special precautions are necessary during installation to prevent damage. (The precautions are described later in the presentation.) NOTE: The sensors maintain a zero clearance with the timing wheel.
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10 • Rueda de Sincronizacion
Esta es la rueda de sincronizacion, fuera del motor
• Ranura y diente 50/50 (fecha)
Notice the wide 50/50 size slot and equal size tooth (arrow) cut in the wheel. Las otras 23 ranuras son de tamaño 80/20 La ranura y diente 50/50 es usada po elECM como punto de referencia para determinar la posocion del motor para la sincronizacion del combustible (se explica completamente mas adelante). El sensor de Speed/Timing puede identificar este diente porque crea una señal diferente que los otros dientes
• Marca de sincronizacion
Una marca de sincronizacion "H," al reverso de larueda de sincronizacion es usada para sincronizar la rueda en relacion a los otros engran. de sincroniz. y el TDC del cigueñal.
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11 • Turbo inlet pressure sensor (arrow)
The Turbo Inlet Pressure Sensor (arrow) is mounted between the air filter and the turbocharger. Not all machines have this sensor installed. This sensor (if installed) is used in conjunction with the atmospheric pressure sensor to measure air filter restriction for engine protection purposes. The difference between the two pressure measurements is used as the filter differential pressure. The engine ECM uses this calculation to determine whether derating is necessary to protect the engine.
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12 • Turbo outlet pressure sensor (arrow)
At the front of the engine in the right cylinder head is the Turbo Outlet (Boost) Pressure Sensor (arrow). This sensor is used with the ECM to control the air/fuel ratio electronically. This feature allows very precise smoke control, which was not possible with mechanically governed engines. The sensor also allows boost pressure to be read using the service tools.
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1
2 4
3
13 • Identify components: 1. Atmospheric pressure sensor 2. Fuel temperature sensor 3. Primary speed/timing sensor 4. Secondary speed/timing sensor
The Atmospheric Pressure Sensor (1) is installed on the Hydraulic Supply Pump Group adapter and is vented to the atmosphere. This sensor has various functions which are fully described later in the presentation. A foam block below the sensor helps prevent the entry of dirt into the sensor. Briefly, the sensor performs the following functions: - Ambient pressure measurement for automatic altitude compensation and automatic air filter compensation. - Absolute pressure measurement for the fuel ratio control, ET, Caterpillar Monitoring System panel (gauge) pressure calculations. The Fuel Temperature Sensor (2) is used for automatic fuel temperature compensation. The Primary (3) and Secondary (4) Speed/Timing Sensors (discussed earlier) are located on the rear of the timing gear housing.
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1 2
3 4
14 1. Aceite de suministro
2. Valvula Compensadora 3. Valvula de control bomba
4. Bomba trasnferencia
A number of components are mounted on the Hydraulic Supply Pump Group. The Oil Supply Line (1) from the oil gallery is a large diameter line for maximum delivery during cold operation. The hydraulic pump depends on the lubrication pump for the first stage of pressure increase. The Compensation Valve (2) is mounted at the rear of the pump. Below the compensation valve is the Pump Control Valve (3). This valve may also be referred to as the "injection actuation pressure control valve." This valve controls the angle of the swashplate, which varies the output of the pump. The Fuel Transfer Pump (4) is mounted at the rear of the Hydraulic Supply Pump and is driven by the main drive shaft which extends through the supply pump. Also visible in this slide are the transfer pump inlet and outlet fuel lines and the pressure and temperature sensors (discussed earlier).
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15 • Lubrication oil pump
Mounted internally in the oil pan is the Bomba de aceite de lubricacion. This pump supplies oil at approximately 400 kPa (65 psi) to the oil gallery for engine lubrication.
• Supplies oil to lubrication and hydraulic injection actuation systems
Oil is also supplied to the hydraulic pump for injection actuation purposes. For this reason, the HEUI engine lubrication oil pump is larger than the pump in the previous engine to accommodate the increased needs of the lubrication and the hydraulic injection actuation systems.
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16 • Timing calibration sensor (arrow)
The Timing Calibration Sensor (arrow) is installed when required in the flywheel housing. This sensor (magnetic pickup) is installed in the hole normally reserved for the timing pin. (The pin is used to position the crankshaft with the No. 1 piston at top dead center.) NOTE: On some applications (i.e. some track-type tractors) where accessibility is limited, this sensor is permanently installed.
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2 1
17 1. Water separator and primary filter
The Water Separator (1), which also functions as a Primary Fuel Filter, is an important part of the fuel system. As with any high pressure fuel system with operating pressures at approximately 150000 kPa (22000 psi), fuel quality is important. Water in the fuel can cause corrosion of the plungers and barrels. Dirt can cause early hour wear on the same components. The water separator contains a 30 micron filter. The Priming Pump is mounted on the filter base.
2. Two micron secondary filter
• Water separator service intervals
For the same reason, the correct two micron Secondary Filter (2) must be used in the system. The clearance between the plunger and barrel is approximately 5 microns. Typically, the 3 to 8 micron abrasive material prematurely wears out the fuel system components. The Water Separator is serviced daily by draining the water. The Water Separator filter is serviced with a new element every 500 hours. INSTRUCTOR NOTE: The high fuel pressures mentioned in this text are mandated by the need to meet environmental regulations for smoke and emissions. Also, to maintain good fuel consumption, high pressures are required. The HEUI system meets and surpasses those requirements.
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3408E/3412E HEUI SYSTEM
8 OR 12 INJECTORS
COMPONENT DIAGRAM ADEM II ELECTRONIC CONTROL MODULE (ECM)
ENGINE HARNESS
MACHINE HARNESS
GROUND BOLT
15 AMP BREAKER
DISCONNECT SWITCH
MAIN POWER RELAY
24 V KEY SWITCH
PUMP CONTROL VALVE MACHINE INTERFACE CONNECTOR
HYDRAULIC PRESSURE SENSOR PRIMARY SPEED/TIMING SENSOR
TDC SERVICE PROBE ACCESS
THROTTLE SENSOR
ACCELERATOR PEDAL
SECONDARY SPEED/TIMING SENSOR
THROTTLE BACK-UP, ELEVATED LOW IDLE ENABLE, AND GROUND LEVEL SHUTDOWN (2) SWITCHES TURBO INLET PRESSURE SENSOR
COOLANT TEMP. SENSOR
FAN CONTROL VALVE TURBO OUTLET PRESS. SENSOR FAN SPEED SENSOR FAN
ATMOSPHERIC PRESS. SENSOR CAT DATA LINK
ELECTRONIC SERVICE TOOL
OIL PRESSURE SENSOR
EPTC II TRANSMISSION CONTROL HYDRAULIC TEMP. SENSOR
AUTO RETARDER CONTROL
FUEL TEMPERATURE SENSOR INSTRUMENT PANEL
COOLANT FLOW SWITCH
18 • Engine component identification
This schematic identifies the external HEUI engine components (shown on the engine harness side of this schematic). The components shown on the left side of the diagram are mounted on the engine and those on the right are machine mounted. Notice that the turbo inlet pressure sensor is mounted on the machine. INSTRUCTOR NOTE: At this time, it is recommended that each component be located on the machine and the function of each reviewed with the students. A list of the components follows on the next page. Some additional (used/defective) components available for examination on a table will be helpful. An ECM with the Personality Module and various sensors can be examined at this time and used for troubleshooting exercises later.
➥
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Electrical Components Conector del ECM 40 Pins Modulo de Personalidad Timing Calibration Connector and Installation Location Sensor de presion hhidraulica Sensor de Temperatura Hidraulica Primary Speed Timing Sensor Secondary Speed Timing Sensor Sensor de Temperatura de Refrigerante Sensor de Presion Atmosferica Sensor de presion de entrada del turbo Sensor de presion de salida del turbo Sensor de presion de aceite Sensor de Temperatura de combustible Switch de flujo de refrigerante Conector de interfase a la maquina Pernos de tierra de motor y de maquina Conector al Data Link Sensor de posicion de acelerador Switches de apagado Componentes Mecanicos Grupo de bomba de suministro de aceite Valvula de control de la bomba Valvula de Compensacion Reservorio para arranque en frio Valvulas check Manifold de fluido Filtro Primario / Separador de agua Filtro secundario Bomba de transferencia Valvula Reguladora de presion Inyector Tubo Jumper Adaptador de aceite para inyector
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SISTEMA DE CONTROL DE ELECTRONICO
19 ELECTRONIC CONTROL SYSTEM This section of the presentation explains the Electronic Control System including the following components: ECM Personality Module Hydraulic Electronic Unit Injector Solenoids Timing Wheel Also covered are the following subsystems and related procedures: Timing control Fuel quantity control Speed control Cold modes Timing calibration
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20 • ECM: - Governor - Fuel system computer - Injection pressure controller - Injection timing controller • Same ECM used in all applications
The Electronic Control Module (ECM) functions as the governor and fuel system computer. The ECM receives all the signals from the sensors and energizes the injector solenoids to control timing and engine speed. The ECM is sealed except for access to the software which is contained in the Personality Module (next slide). This ECM is the second generation of Advanced Diesel Engine Management Systems and may be frequently referred to as "ADEM II." This ECM is used in all applications of the 3408E and 3412E engines. The ECM can also be moved from one application to another; however, a password is required to activate the ECM when new software is installed. NOTE: The ECM has an excellent record of reliability. Therefore, any problems in the system are most likely to be in the connectors and wiring harness. In other words, the ECM should typically be the last item in troubleshooting.
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21 • Personality module contains software
The Personality Module (shown removed from the ECM) contains the software with all the fuel setting information (such as horsepower, torque rise and air/fuel ratio rates) which determines how the engine will perform. The Personality Module is installed on the lower face of the ECM, behind the access panel. At this time, two methods can be used to update the software:
• Two methods to upgrade software
1. Flash Programming: Electronic reprogramming of the Personality Module software. (This method is preferred when updating the software.) 2. Remove and replace the Personality Module. (This method may be used if Flash Programming is not possible.) Upgrading the software is not a routine task, but might be performed for reasons of a product update, a performance improvement or a product problem repair.
• ECM is sealed except for personality module
NOTE: The ECM is sealed and needs no routine adjustment or maintenance. The Personality Module is mounted within the ECM. Installation of the Personality Module is the only reason to enter the ECM. This operation would normally be performed during an ECM installation or a software update.
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22 Fuel Injection • Unit injectors • Electrically signalled, hydraulically actuated
The 3400 HEUI unit injector is electrically similar to the 3500 electronic unit injector. The injector is controlled electrically by the ECM but is actuated hydraulically. The signal from the ECM controls the opening and closing of the solenoid valve. The solenoid valve controls the flow of high pressure hydraulic oil to the injector. This system enables the ECM to control fuel volume, timing and injection actuation pressure (hydraulic supply pump pressure).
The injector solenoids operate on 105 Volts direct current. Always remain clear of the injector area when the engine is running or electric shock may occur.
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METODOS DE PRUEBAS EN INYECTORES HEUI
PRUEBA DE SOLENOIDES DE INYECTOR CORTE DE CILINDROS PRUEBA AUTOMATICA DE INYECTORES
23 Three tests can be used to determine which cylinder or injector is malfunctioning: • Injector testing
INJECTOR SOLENOID TEST This test is performed while the engine is stopped. The injector solenoids can be tested automatically with the service tool using the Injector Solenoid Test. This function individually tests each solenoid in sequence and indicates if a short or an open circuit is present. CYLINDER CUT-OUT (Manual test) This test is performed while the engine is running at any speed. The 105 Volt pulse can be individually cut out to aid in troubleshooting misfire problems in the injector and the cylinder. AUTOMATIC INJECTOR TEST This test is performed with the service tool while the engine is running at any speed. The test makes a comparative evaluation of all injectors and numerically shows the results. The test enables an on-engine evaluation of the injectors. (This test cannot be performed using the ECAP.) A satisfactory test of all injector solenoids without any diagnostic messages indicates that a mechanical problem in the cylinder probably exists.
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LOGICA DE CONTROL DE HEUI TIMING CONTROL VELOCIDAD DE MOTOR CANTIDAD DE COMBUSTIBLE
TEMPERATURA DE ACEITE A ALTA PRESION
TIMING
DEGREES BTDC
FUEL RPM SELECT TIMING
DESIRED TIMING BTDC
CONVERT DESIRED TIMING
FUEL INJECTION TIMING WAVE FORM
MODO FRIO
24 Fuel Injection Control System • Fuel timing control
• Inputs to timing control
This diagram shows the timing control logic within the ECM. Engine speed, fuel quantity (which relates to load), and hydraulic oil temperature input signals are received by the timing control. The hydraulic temperature signal determines when the Cold Mode should be activated. These combined input signals determine the start of fuel injection. The timing control provides the optimum timing for all conditions. The benefits of a "smart" timing control are:
• Benefits of a "smart" timing control
- Reduced particulates and lower emissions - Improved fuel consumption while still maintaining performance - Extended engine life - Improved cold starting
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3408E/3412E ELECTRONIC GOVERNOR HYDRAULIC OIL TEMPERATURE AND PRESSURE SENSORS
SHUTDOWNS TO PUMP CONTROL VALVE
8 SIGNALS 7 TO FUEL 6 INJECTORS 5 4 3 2 1
ECM
INJECTION ACTUATION CONTROL
FUEL INJECTION CONTROL
SPEED/TIMING SIGNAL
ELECTRONIC GOVERNOR
ENGINE RPM
FRC MAPS
TORQUE MAPS
ENGINE CONTROL LOGIC
THROTTLE
TDC ENGINE RPM
ENGINE RPM TURBO OUTLET AND ATMOSPHERIC PRESSURE SENSORS
TIMING WHEEL SPEED/TIMING SENSORS
25 • Fuel quantity control • Inputs to fuel quantity control
Four inputs control fuel quantity: 1. Engine speed 2. Injection actuation (hydraulic) pressure 3. Throttle position 4. Boost
• Start of injection determines timing • Injection duration and injection actuation pressure determine fuel quantity
These signals are received by the electronic governor portion of the ECM. The governor then sends the desired fuel signal to the fuel injection and injection actuation controls. The fuel quantity control logic also receives signals from the fuel ratio and torque controls. Three variables determine fuel quantity and timing: - The start of injection determines engine timing. - The injection duration and injection actuation (hydraulic) pressure determine the quantity of fuel to be injected.
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HEUI SYSTEM
8 OR 12 INJECTORS
ADEM II ELECTRONIC CONTROL MODULE (ECM)
ENGINE HARNESS
MACHINE HARNESS
COMPONENT DIAGRAM
GROUND BOLT
DISCONNECT SWITCH 24 V
MAIN KEY 15 AMP POWER RELAY SWITCH BREAKER
PUMP CONTROL VALVE MACHINE INTERFACE CONNECTOR
HYDRAULIC PRESSURE SENSOR PRIMARY SPEED/TIMING SENSOR
TDC SERVICE PROBE ACCESS
THROTTLE SENSOR
ACCELERATOR PEDAL
SECONDARY SPEED/TIMING SENSOR
THROTTLE BACK-UP, ELEVATED LOW IDLE ENABLE, AND GROUND LEVEL SHUTDOWN (2) SWITCHES TURBO INLET PRESSURE SENSOR
COOLANT TEMP. SENSOR
PROPORTIONAL VALVE TURBO OUTLET PRESS. SENSOR FAN SPEED SENSOR FAN
ATMOSPHERIC PRESS. SENSOR CAT DATA LINK
ELECTRONIC SERVICE TOOL
OIL PRESSURE SENSOR
EPTC II TRANSMISSION CONTROL HYDRAULIC TEMP. SENSOR
AUTO RETARDER CONTROL
FUEL TEMPERATURE SENSOR INSTRUMENT PANEL
COOLANT FLOW SWITCH
26 • Speed/timing sensors
• Three functions of the speed/timing sensor
Two Speed/Timing Sensors are installed: a primary and a secondary. The Speed/Timing Sensors serve three functions in the system: 1. Engine speed measurement 2. Engine timing measurement 3. Cylinder and TDC location The Speed/Timing Sensors, which are mounted on the front housing below the timing gear wheel, are self-adjusting during installation and have zero clearance with the timing wheel.
• Sensor installation
The head is extended prior to installation. The action of screwing in the sensor pushes the head back into the body until the head contacts the timing wheel. This contact is only momentary while the engine is starting. After start-up, the head runs with zero clearance.
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SECONDARY SPEED/TIMING SENSOR
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SPEED/TIMING SENSORS P44 J44 OR BK WH
A B C P2 J2
PRIMARY SPEED/TIMING SENSOR
ECM (3408E/3412 E) P20 J20 OR BK WH
TIMING CALIBRATION CONNECTOR
732-PK 996-GN 998-BR 999-WH F723-PK F724-PU
A B C
P26 1 2
39 32 29 38 18 12
SECONDARY ENGINE SPEED +V TIMING DIGITAL RETURN PRIMARY ENGINE SPEED TIMING CAL + TIMING CAL -
P1 J1
27 • Primary sensor
The Primary Speed/Timing Sensor (right side of engine) measures engine speed for governing, and crankshaft position for timing purposes and cylinder identification.
• Secondary sensor
The Secondary Speed/Timing Sensor (left side of engine) allows continuous operation if the primary sensor fails. A failure of the primary sensor will cause the ECM to automatically switch to the secondary sensor. Also, the check engine lamp will come on.
• Power supply
The ECM supplies 12.5 ± 1 Volts to the Primary and Secondary Speed/Timing Sensors. Connectors A and B transmit the common power supply to the sensors. The C connectors transmit separate signals from each sensor to the ECM for back-up purposes. NOTE: The Speed/Timing Sensors have a dedicated power supply. No other circuits should be spliced into this power supply.
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28 • Timing wheel
The Timing Wheel is an integral part of the drive gear for the pump. Timing marks are used to locate the wheel in the correct position relative to the crankshaft. This Timing Wheel is common to all 3408E/3412E engines. As previously stated, the Timing Wheel has a total of 24 teeth. 23 teeth are large with small spaces between them (80/20 relative size). The other tooth and space have equal dimensions (50/50 relative size). This configuration is used by the ECM to locate TDC on the No. 1 cylinder.
NOTICE The head of the sensor MUST NOT be positioned in the timing wheel (wide) slot during installation. Incorrect positioning will cause damage to the sensor head.
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TIMING WHEEL REF
TDC REF
SECONDARY SPEED/TIMING SENSOR
TDC
4
SINGLE 50/50 TOOTH TDC CYLINDER No. 1
8
3
PRIMARY SPEED/TIMING SENSOR
REF TDC REF
TIMING CALIBRATION RANGE ± 10°
1 6
REF
TDC TIMING WHEEL ROTATION
TDC REF 2
5
7
TDC
REF TDC
REF
29 The Speed/Timing Sensors are positioned vertically over the teeth. • Sensors generate a PWM signal from timing wheel teeth
The teeth and sensors generate a Pulse Width Modulated (PWM) output signal for the purpose of timing and a frequency modulated output signal for speed measurement.
• Failure modes
The Secondary Speed/Timing Sensor functions the same as the primary sensor. The Secondary Speed/Timing Sensor is used when the signal from the primary sensor is lost or distorted. If the secondary sensor is selected, it will continue in use until the engine is shut down and cranked. Then, the primary sensor will be selected. Unless the engine is cranking, the ECM will not switch from the secondary to the primary sensor. This feature prevents constant switching between sensors if an intermittent fault occurs. INSTRUCTOR NOTE: A description of PWM signals is provided later in this presentation (Sensors and Systems).
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CRANKING TIMING GEAR TOOTH TABLE TABLE PWM DUTY CYLINDER ENTRY REFERENCE CYCLE A B C D E F G H
80/20 %
A
B
80 % 80 % 80 % 80 % 80 % 80 % 80 % 50 %
80/20 %
C
NONE IDENTIFIED
80/20 %
80/20 %
D
E
80/20 %
F
80/20 %
G
50/50%
H
TIMING WHEEL ROTATION
30 • Cranking • Timing wheel teeth and spacing
The Speed/Timing Sensor uses the timing wheel with the teeth arranged as shown to determine: - Top Dead Center No. 1 (When found, the cylinders can be identified.) - Engine speed The sequence of signals shown in the second column (duty cycle) is analyzed by the ECM. At this point, no fuel will be injected until certain conditions have been met. Unlike EUI engines, this engine does not rely on tooth configuration to prevent reverse rotation. The lubrication and the hydraulic pumps will not develop pressure during reverse rotation, and will not move the injectors to pump fuel. Therefore, the engine cannot run in reverse.
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AFTER PATTERN RECOGNITION TIMING GEAR TOOTH TABLE TABLE PWM DUTY CYLINDER CYCLE ENTRY REFERENCE 80 % 80 % 80 % 80 % 80 % 80 % 80 % 50 %
A B C D E F G H
NO CYL NO. 3 NO NO CYL NO. 4 NO NO CYL NO. 8 TIMING WHEEL ROTATION
A
B
CYL NO. 3 REFERENCE EDGE
C
D
CYL NO. 3 TDC
E
CYL NO. 4 REFERENCE EDGE
F
G
CYL NO. 4 TDC
H
CYL NO. 8 REFERENCE EDGE
31 • After pattern recognition
During start-up, the sensor initially monitors the pulses created by the passing teeth and identifies the sequence as shown. After a complete rotation, the control can recognize the location of TDC from the pattern in the above illustration.
• Initial firing sequence
During initial cranking, no fuel is injected until: The timing wheel has completed a full revolution. TDC for all cylinders is identified by the control. After the sensor has provided the necessary signals, the ECM is ready to start injection (if sufficient hydraulic pressure is available to the injectors). NOTE: The reference points in the illustration are positions on the timing wheel from which the control measures the point of injection and TDC.
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TIMING GEAR TOOTH TABLE TABLE PWM DUTY CYLINDER ENTRY CYCLE REFERENCE A B C D E F G H
80 % 80 % 80 % 80 % 80 % 80 % 80 % 50 %
NORMAL OPERATION
NO CYL NO. 3 NO NO CYL NO. 4 NO NO CYL NO. 8 TIMING WHEEL ROTATION
A
B
C
D
E
62° BTDC (EEPROM)
CYL NO. 3 (REFERENCE)
G
H
62° BTDC (EEPROM) DES TIMING
DES TIMING DELAY
F
NO. 3 INJECTION
DELAY
ASSUMED TDC
CYL NO. 3 ACTUAL TDC (CALIBRATED)
NO. 4 INJECTION
ASSUMED TDC
CYL NO. 4 (REFERENCE)
CYL NO. 4 ACTUAL TDC (CALIBRATED)
32 • Normal operation
• Signal pattern identifies TDC • Conditions for injection
During normal operation, the ECM can determine timing from the sequence reference point for each cylinder. The reference point is stored by the ECM after calibration is performed. Injection timing is calibrated by connecting a TDC probe to the service access connector on the engine harness, and by activating the calibration sequence with the Caterpillar ET service tool. The ECM raises the engine speed to 800 rpm (to optimize measurement accuracy), compares the actual No. 1 TDC location to the assumed cylinder No. 1 TDC location, and saves the offset in the EEPROM (Electrically Erasable Programmable Read Only Memory).
NOTE: The calibration offset range is limited to ± 10 crankshaft degrees. If the range is exceeded, the offset is set to zero (no calibration) and a calibration diagnostic message is generated.
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TIMING CALIBRATION SENSOR SECONDARY SPEED/TIMING SENSOR
P44 J44 OR BK WH
A B C P2 J2
PRIMARY SPEED/TIMING SENSOR
ECM (3408E/3412E) P20 J20 OR BK WH
TIMING CALIBRATION SENSOR
732-PK 996-GN 998-BR 999-WH F723-PK F724-PU
A B C
39 32 29 38 18 12
SECONDARY ENGINE SPEED +V TIMING DIGITAL RETURN PRIMARY ENGINE SPEED TIMING CAL + TIMING CAL -
P1 J1 P26 1 2
TIMING CALIBRATION CONNECTOR
33 • Timing calibration sensor
The Timing Calibration Sensor (magnetic pickup) is installed in the flywheel housing during calibration. The connector is located above the ECM. (On some machines, i.e. D9R/D10R, the sensor is permanently installed.) Using the Caterpillar ET service tool, timing calibration is performed automatically for both sensors when selected on the appropriate screen. The desired engine speed is set to 800 rpm. This step is performed to avoid instability and ensures that no backlash is present in the timing gears during the calibration process.
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TIMING CALIBRATION TIMING WHEEL
REFERENCE EDGE TO TDC DISTANCE REFERENCE EDGE
ASSUMED CYL. NO. 1 TDC
-10° TIMING CALIBRATION SENSOR SIGNAL
+10° ± 10°
ACTUAL CYL. NO. 1 TDC
TIMING REFERENCE OFFSET
MAXIMUM TIMING REFERENCE OFFSET ± 10 DEGREES
34 • Timing calibration
• Nulls out small crankshaft to timing gear tolerances
As the Speed/Timing Sensors use the timing wheel for a timing reference, timing calibration improves fuel injection accuracy by correcting for any slight tolerances between the crankshaft, timing gears and timing wheel. During calibration, the offset is logged in the control module EEPROM (Electrically Erasable Programmable Read Only Memory). The calibration offset range is limited to ± 10 crankshaft degrees. If timing is out of range, calibration is aborted. The previous value will be retained and a diagnostic message will be logged. Timing calibration is normally performed after the following procedures: 1. ECM replacement 2. Speed/timing sensor replacement 3. Timing wheel replacement
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INJECTION CURRENT WAVEFORM
CURRENT FLOW
ONE CYCLE
PULL-IN PEAK CURRENT
HOLD-IN PEAK CURRENT
0
1
2
3
4
5
TIME (MILLISECONDS)
35
• Unit injector current flow
This illustration shows how the current increases initially to pull in the injection coil and close the poppet valve. Then, by rapidly chopping (pulsing) the 105 Volts on and off, current flow is maintained. The end of injection occurs when the current supply is cut off and hydraulic pressure drops. Therefore, fuel pressure drops rapidly in the injector.
INSTRUCTOR NOTE: This waveform may be demonstrated with a 9U7330 Digital Multimeter (or equivalent) and a current probe.
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POPPET VALVE MOVEMENT
CURRENT FLOW
POPPET LIFT
CURRENT
0
1
2
3
4
5
TIME (MILLISECONDS)
36 • Poppet valve movement
This diagram shows that the poppet valve will open just after the ECM energizes the solenoid. The poppet valve permits hydraulic oil to shift the injector intensifier piston which then moves the injector plunger.
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WAVEFORM AND RESPONSE CHARACTERISTICS INJECTION RATE
CURRENT FLOW
POPPET LIFT
CURRENT
END OF INJECTION START OF INJECTION
0
1
DURATION
2
3
4
5
TIME (MILLISECONDS)
37 • Timing relative to: 1. Injector current flow 2. Poppet valve movement
Here timing is graphically illustrated to show: 1. The ECM initiates the signal to the injector to start injection. 2. The injector solenoid opens the poppet valve. 3. The injection rate increases.
3. Injection rate
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FUEL SYSTEM COLD MODES • • • • •
Speed Control Fuel Limiting Injection Timing Injection Actuation Pressure Ether Injection
38 • Fuel system limits
Just as the MUI engine had mechanical limits to determine maximum fuel delivery during full load, full torque and acceleration, the HEUI system also has electronic limits to protect the engine. These limits are: - Maximum Horsepower - Torque Limit (Determines torque rise characteristics) - Fuel Ratio Control (Limits fuel until sufficient boost is available) - Cold Mode Limit (Limits fuel with cold engine to control white smoke) - Cranking Limit (Limits fuel during cranking) An acceleration delay during start-up holds the engine at low idle for two seconds or until oil pressure reaches 140 kPa (20 psi).
• Variable horsepower
• Economy Shift Mode
Off-highway Trucks have a system which increases engine horsepower in direct drive only. This system protects the driveline from excessive torque in the lower gears. Off-highway Trucks also have a service tool programmable feature which is designed to lower shift points and the fuel limit to improve fuel consumption at the customer's request.
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FUEL SYSTEM COLD MODES • • • • •
Speed Control Fuel Limiting Injection Timing Injection Actuation Pressure Ether Injection
39 • Cold modes
The HEUI fuel system is designed to modify the operational characteristics of the engine during cold operation. This modification is done to protect the environment, the engine and to improve the operational characteristics of the engine. INSTRUCTOR NOTE: The various Cold Modes are tabulated in Serviceman's Handout No. 2. Discuss how these Cold Mode variations can change the engine characteristics, particularly during diagnostic operations. For example: - Injection actuation pressure will vary with engine temperature. - Engine speed may be raised in Cold Mode.
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FUEL SYSTEM DERATES • Automatic Altitude Compensation • Automatic Filter Compensation • Engine Warning Derate
40 • Fuel system derates
As the system limits fuel for every condition, derates are also built into the system for protection. These derates are individually covered later in the presentation, but are summarized here: - Automatic Altitude Compensation (Altitude derate) - Automatic Filter Compensation (Derates for air filter restriction if installed) - Engine Warning Derate (Derates for low oil pressure and high coolant temperature; not installed on all applications)
If a loss of boost sensor output occurs, the ECM assumes zero boost pressure. Although not strictly a derate, power is reduced by approximately 50 to 60%. • Power correction
- Fuel Temperature Compensation (Compensates up to 5% for power loss caused by hot fuel)
➥
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INSTRUCTOR NOTE: This material will be reinforced if the following ET tasks are demonstrated. Review the material with questions following the tasks. The demonstration can be performed on an engine or machine with a laptop computer. The suggested topics are: Basic ET review (if required) Status screens with throttle switch status, desired engine speed, fuel position, injection actuation pressure, etc. Active diagnostic codes Logged diagnostic codes Events screen Configuration screen Timing calibration Injector solenoid test Cylinder cutout Automatic injector test
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FUEL INJECTION SYSTEM
41 FUEL INJECTION SYSTEM This portion of the presentation describes the principles of operation of the HEUI Fuel Injection System as is used on the 3408E and 3412E engines. INSTRUCTOR NOTE: The various color codes which will be used in this section of the presentation to identify flow and pressures are: Hydraulic and Lubrication Circuits Red
- High pressure oil
Red and White Stripes
- Reduced pressure oil
Brown
- Lube oil pressure
Green
- Lube oil suction or return
Fuel Circuits Red
- High pressure fuel
Red and White Stripes
- Fuel transfer pump pressure
Green
- Fuel suction or return
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3408E/3412E HEUI FUEL SYSTEM TO LUBE SYSTEM
HEUI HYDRAULIC TEMPERATURE SENSOR
COLD START OIL RESERVOIR
OIL FILTER
COOL DOWN CIRCUIT
HYDRAULIC SUPPLY PUMP GROUP
OIL COOLER
FLUID MANIFOLD HYDRAULIC PASSAGE
OIL PRESSURE SENSOR
HYDRAULIC PRESSURE SENSOR
FUEL TEMPERATURE SENSOR
FLUID MANIFOLD HYDRAULIC PASSAGE
PUMP CONTROL VALVE FUEL TRANSFER PUMP
LUBE OIL PUMP
PRIMARY FUEL FILTER WATER SEPARATOR OIL SUMP
HEUI
ECM
SECONDARY FUEL FILTER
PRESSURE REGULATING VALVE
FUEL TANK
42 Actuation of the fuel injection system is accomplished using hydraulics, rather than the conventional camshaft actuation commonly found on other diesel fuel systems. Hydraulic actuation offers several advantages compared to mechanical actuation, including the ability to make injection pressure independent of engine operating speed. This capability is especially advantageous in many respects, including transient engine response, cold starting, emissions and noise control. INSTRUCTOR NOTE: The following schematics may appear identical in the black and white illustrations. However, the actual slides are colored differently.
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1 2
3
5 4
43 System Components • HEUI principle components:
1. Hydraulic supply pump group
To review, the 3400 HEUI hydraulic and fuel supply circuits contain the following major components: • Hydraulic Supply Pump Group (1) including: - Hydraulic pump - Fuel transfer pump
2. ECM
- Pump control valve 3. Temperature sensor
• Electronic Control Module (ECM) (2) • Electronic Sensors (3 and 4) - Hydraulic temperature
4. Pressure sensor
5. Injector
- Hydraulic pressure • Injectors (5)
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1
2 3
44 • Hydraulic supply pump group: 1. Hydraulic pump
The following components are integrated into a single unit called the Hydraulic Supply Pump Group: - Hydraulic pump (1) - Pump control valve (2)
2. Pump control valve
3. Transfer pump
- Transfer pump (3) This pump group is located in the vee of the engine and is in the same position as the fuel injection pump on earlier engines. Three fluid circuits are included in the system: low pressure oil, high pressure oil (hydraulic), and low pressure fuel supply. NOTE TO THE INSTRUCTOR: These components and circuits will be covered in detail later in the presentation.
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3408E/3412E HEUI FUEL SYSTEM TO LUBE SYSTEM
LOW PRESSURE OIL (HYDRAULIC) SUPPLY HEUI HYDRAULIC TEMPERATURE SENSOR COLD START OIL RESERVOIR
OIL FILTER
FLUID MANIFOLD HYDRAULIC PASSAGE
OIL PRESSURE SENSOR COOL DOWN CIRCUIT
HYDRAULIC SUPPLY PUMP GROUP
FUEL TEMPERATURE SENSOR
HYDRAULIC PRESSURE SENSOR
FLUID MANIFOLD HYDRAULIC PASSAGE
PUMP CONTROL VALVE
HEUI ECM
OIL COOLER FUEL TRANSFER PUMP
LUBE OIL PUMP
SECONDARY FUEL FILTER
PRESSURE REGULATING VALVE
PRIMARY FUEL FILTER WATER SEPARATOR OIL SUMP
FUEL TANK
45 System Operation On a HEUI equipped engine, the lubrication pump has two functions: • Low pressure oil supply
1. Provides lubrication to the engine 2. Provides low pressure charge oil to the HEUI hydraulic pump The engine lubrication pump has been enlarged to provide the required increase in flow.
• Cold start reservoir
• Pressure sensor • Temperature sensor
The hydraulic pump has a Cold Start Oil Reservoir. This reservoir prevents the hydraulic pump from cavitating during initial engine cranking until the lubrication pump can supply adequate charge pressure. An oil pressure sensor is located in the Cold Start Oil Reservoir, which is the inlet to the hydraulic oil pump. The sensor monitors lubrication oil pressure. An oil temperature sensor is also installed in the reservoir. This sensor will be referred to as the "hydraulic temperature sensor" as it is used for this purpose.
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3408E/3412E HEUI FUEL SYSTEM TO LUBE SYSTEM
HIGH PRESSURE HYDRAULICS HEUI HYDRAULIC TEMPERATURE SENSOR COLD START OIL RESERVOIR
OIL FILTER
FLUID MANIFOLD HYDRAULIC PASSAGE
OIL PRESSURE SENSOR COOL DOWN CIRCUIT
HYDRAULIC SUPPLY PUMP GROUP
FUEL TEMPERATURE SENSOR
HYDRAULIC PRESSURE SENSOR
FLUID MANIFOLD HYDRAULIC PASSAGE
PUMP CONTROL VALVE
HEUI ECM
OIL COOLER FUEL TRANSFER PUMP LUBE OIL PUMP
SECONDARY FUEL FILTER
PRESSURE REGULATING VALVE
PRIMARY FUEL FILTER WATER SEPARATOR OIL SUMP
FUEL TANK
46
• High pressure actuates hydraulics
During normal operation conditions, oil is pressurized between 5000 and 21500 kPa (725 and 3100 psi) by the high pressure hydraulic pump to actuate the injectors. The level of hydraulic pressure is controlled by the ECM, which signals the pump control valve to upstroke the hydraulic pump. When the engine is running, high pressure oil is available to all injectors at all times. Oil from the high pressure pump enters the two oil supply passages. Reverse flow check valves are used to prevent pressure surges between the oil passages on opposite banks. The oil supply passages are connected hydraulically to the injectors by jumper tubes. Oil used by the injectors is released below the valve covers and drains back to the sump through the pushrod compartments.
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3408E/3412E HEUI FUEL SYSTEM TO LUBE SYSTEM
LOW PRESSURE FUEL SUPPLY HEUI HYDRAULIC TEMPERATURE SENSOR COLD START OIL RESERVOIR
OIL FILTER
FLUID MANIFOLD HYDRAULIC PASSAGE
OIL PRESSURE SENSOR
HYDRAULIC PRESSURE SENSOR
FUEL TEMPERATURE SENSOR
COOL DOWN CIRCUIT
HYDRAULIC SUPPLY PUMP GROUP
FLUID MANIFOLD HYDRAULIC PASSAGE
PUMP CONTROL VALVE
HEUI ECM
OIL COOLER FUEL TRANSFER PUMP
LUBE OIL PUMP
SECONDARY FUEL FILTER (2 MICRON)
PRIMARY FUEL FILTER WATER SEPARATOR OIL SUMP
PRESSURE REGULATING VALVE
FUEL TANK
47 • Low pressure fuel supply
• Injector cooling
Fuel is drawn from the tank through the water separator and the hand priming pump by a gear-type transfer pump. The fuel is then directed through the Electronic Control Module (ECM) housing for cooling purposes. The fuel then flows through the secondary fuel filter. Next, the fuel enters the low pressure supply gallery located in the fluid supply manifolds on top of the cylinder heads. Any excess fuel not injected leaves the manifold. The flow is then combined into one line and passes through the pressure regulating valve, which is set between 310 and 415 kPa (45 and 60 psi). From the pressure regulating valve, the excess flow returns to the tank. The ratio of fuel between combustion and fuel returned to the tank is about 1:3 (i.e. four times the volume required for combustion is supplied to the system for combustion and injector cooling purposes). A fuel temperature sensor is installed in the fuel supply system to compensate for power losses caused by varying fuel temperatures.
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INJECTOR FLUID FLOW
HIGH PRESSURE HYDRAULIC OIL
INJECTOR OIL ADAPTER
INJECTOR CLAMP JUMPER TUBE
ROCKER ARM BASE INJECTOR LUBE OIL PASSAGE HIGH PRESSURE HYDRAULIC PASSAGE
FLUID SUPPLY MANIFOLD CYLINDER HEAD INJECTOR SLEEVE CYLINDER HEAD LOW PRESSURE FUEL SUPPLY
COOLANT CYLINDER BLOCK METAL WASHER
48 Hydraulic Unit Injector Operation • Fuel and oil flow
High pressure hydraulic oil is provided to each injector from the hydraulic supply passages through individual jumper tubes. Fuel is supplied to the injector by the low pressure supply passage located in the fluid manifolds (described on the next slide). Special "Viton" o-rings are used in the hydraulic joints between the injector and the fluid manifold. NOTE: This slide and the following slide depart from the color legend by using orange for high pressure oil to avoid confusion between the two fluids.
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INJECTOR FUEL SUPPLY INJECTOR UPPER SLEEVE O-RING SEAL
UPPER INJECTOR O-RING SEAL
CYLINDER HEAD INJECTOR SLEEVE
FLUID SUPPLY MANIFOLD
LOWER SLEEVE O-RING SEAL
LOW PRESSURE FUEL SUPPLY
CYLINDER HEAD METAL-TO- METAL CONTACT
LOWER INJECTOR O-RING SEAL
49 • Low pressure fuel supply to injector
Low pressure fuel is supplied to the inlet of the injector through a drilled passage located in each Fluid Supply Manifold. The fuel supply to each injector is sealed from the combustion chamber and the area below the valve cover by upper and lower o-ring seals between the injector and the cylinder head injector sleeve. Combustion chamber gases are prevented from entering the fuel supply passage by a metal-to-metal contact between the cylinder head injector sleeve and the injector. The cylinder head injector sleeve is threaded into the cylinder head. A metal washer is used to seal the lower end of the adapter to prevent leakage between the cooling system and the combustion chamber.
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1
3
2
50 • Fluid supply manifold • Supply passages: 1. Hydraulic
The following passages are located in the Fluid Supply Manifold: - Hydraulic supply passage (1) - Lubrication supply passage (2)
2. Lubrication 3. Fuel
- Fuel supply passage (3) The fluid supply manifold is mounted on the cylinder head and carries injector actuation hydraulic oil under pressure through the jumper tubes to the injectors. Low pressure fuel and lubrication oil to the valve mechanism are also directed through the manifold. These passages are shown in the sectional view on the next slide.
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FLUID SUPPLY MANIFOLD
FUEL SEALS
ROCKER ARM BASE
CYLINDER HEAD INJECTOR SLEEVE
LOW PRESSURE FUEL SUPPLY PASSAGE
EXTRACTOR LUBRICATION OIL SPLINES PASSAGE
HIGH PRESSURE HYDRAULIC PASSAGE
51 This sectional view shows the various passages in the Fluid Supply Manifold. • Supply passages
- High pressure hydraulic supply passages - Low pressure fuel supply passages - Lubrication oil supply passages
• Additional fuel for cooling
• Fuel seals
The fuel enters the front of the manifold and exits the rear. Cooling of the injectors is achieved by circulating a larger volume of fuel past the injectors than is required for combustion. Initially, fuel circulates around the outside of the injector sleeve and is contained between the sleeve and the fluid supply manifold by the upper and lower injector sleeve fuel seals.
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1 2
52 • Jumper tube and oil adaptor
The Jumper Tube (1) and Injector Oil Adaptor (2) direct hydraulic oil from the fluid manifold high pressure passage to the injector. A specific procedure to tighten the six bolts (for the Jumper Tube and Adaptor) must be followed when installing the jumper tube. This procedure follows later in the presentation.
NOTICE Failure to follow the correct tightening procedure can result in low power complaints caused by internal hydraulic leaks. Also, internal strains on the injector caused by an improper tightening procedure can cause changes in internal injector clearances which can decrease performance and injector life.
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INJECTION CURRENT WAVEFORM
CURRENT FLOW
ONE CYCLE
PULL-IN PEAK CURRENT
HOLD-IN PEAK CURRENT
0
1
2
3
4
5
TIME (MILLISECONDS)
53 • Injector current waveform
Injector Operation Characteristics The quantity of fuel delivered is controlled by varying the time the solenoid is energized. This period of time, called "duration," is calculated by the ECM to ensure delivery of the correct amount of fuel. Other inputs affect calculation of on-time, including (but not limited to) hydraulic supply pressure, oil temperature and mapped injector performance characteristics. Two current levels are generated in the wave form:
• Two current levels
1. Pull-in current is higher to create a stronger magnetic field to attract the armature and lift the injector poppet valve off its seat against spring force. 2. Hold-in current is used to hold the armature and poppet off its seat. Lower current reduces heat in the solenoid and increases solenoid life. The injector performance map shows delivery as a function of on-time, pump pressure, and oil temperature, and is stored in the ECM memory.
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WAVEFORM AND RESPONSE CHARACTERISTICS
INJECTION RATE
CURRENT FLOW
POPPET LIFT
CURRENT
DURATION
0
1
2
START OF INJECTION
3
TIME (MILLISECONDS)
5
4
END OF INJECTION
54 • Waveform and injector response
This slide shows that, as the ECM energizes the solenoid, the poppet valve movement follows. Then, the injector rate increases for the start of injection. The end of injection occurs as the rate drops toward zero. Therefore: • Engine fuel timing is a function of the start of injection. • Fuel quantity is a function of: - The duration of injection - Injection actuation (hydraulic) pressure
➥
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• Pull-in current
The ECM sends a higher current to the solenoid to create a strong magnetic field. This strong field is needed to create maximum pull on the armature, which is at its farthest distance from the solenoid.
• Poppet lift - Blue line
The poppet is normally held on its inlet seat by the poppet spring. The higher pull-in current attracts the armature and lifts the poppet off its inlet seat and toward the exhaust seat against the spring force. The ECM reduces the current level to hold-in current and the poppet is held on its exhaust seat.
• Start of injection - Purple line
Injection starts after the exhaust seat closes and oil pressure pushes the intensifier piston and plunger down. The downward movement of the plunger pressurizes the fuel to approximately 31000 kPa (4500 psi) and the check valve lifts, allowing fuel to enter the cylinder. The time at which fuel leaves the tip is called the "start of injection."
• Injection rate - Purple line
The rate at which fuel is injected is controlled by injection hydraulic pressure. Higher hydraulic pressure pushes the piston and plunger faster, causing a higher flow rate through the nozzle tip.
• End of injection
When the ECM ends injection, it terminates the hold-in current which causes the magnetic field in the solenoid to collapse. The poppet spring then moves the poppet back to the inlet seat. As the poppet travels back to the inlet seat, hydraulic oil is shut off, and the downward travel of the piston and plunger reverses, filling the barrel for the next injection sequence. As pressure drops below the plunger and nozzle areas, the valve closing pressure, which is about 21000 kPa (3000 psi), causes this pressure to be retained in the nozzle for the next cycle.
INSTRUCTOR NOTE: If a disassembled or a cutaway injector is available, it is recommended that the preceding sequence be reviewed using the actual components.
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55 Injector Components The 3408E/3412E unit injector has been designed to represent the state of the art in the industry. This section of the presentation will describe all the components and their functions. This slide shows a cutaway injector and the injector sleeve. Note the following major injector component groups: • Major components
- Valve body group with solenoid and poppet valve - Barrel group with intensifier piston and plunger - Nozzle group
• Seals
The injector sleeve has four seal grooves. The two upper grooves have the seals which contain the fuel within the fluid manifold (shown in more detail later). The two lower seals contain the coolant below the cylinder upper deck. A metal washer seals the lower part of the sleeve and prevents coolant from entering the combustion chamber.
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VALVE BODY GROUP
BARREL GROUP
HEUI UNIT INJECTOR 3 MAIN GROUPS
NOZZLE GROUP
56 The injector consists of three basic groups which will be described in detail: • Three main groups
- Valve Body Group - Barrel Group - Nozzle Group
This view and those that follow show the exhaust port on the injector venting the return oil downward. This condition is a modification from the previous design which vented the oil upward. These injectors are interchangeable. However, the newer injector reduces the tendency of the engine to discharge oil mist from the breather.
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3408E/3412E HEUI INJECTOR COMPONENTS
VALVE BODY GROUP
BODY
ADAPTER BOLT
POPPET
SPRING SLEEVE SHIM SEAL
SOLENOID ASSEMBLY
ARMATURE
SPACER
SCREW
SCREW
SEAL INTENSIFIER PISTON RETAINER RING
BARREL GROUP
WASHER
NOZZLE GROUP BALL
DOWEL
PLUNGER
SPRING
SEAL
BARREL
BALL
STOP CHECK PLATE PLATE
DOWEL
STOP
LIFT SPACER
DOWEL
TIP
CASE
STOP SPRING SLEEVE CHECK PIN
57 • Injector components
The HEUI injector was designed with a minimum of component parts. The injector contains 35 part numbers. This exploded view shows all the components by assemblies as follows: The Valve Body Group contains the solenoid, armature and the poppet valve. This assembly directs the oil to the hydraulic intensifier piston which moves the fuel plunger. The Barrel Group contains the high pressure fuel plunger. The Nozzle Group contains the case, tip, check valve and nozzle. NOTE: Although the injector components are explained in this presentation, it should be noted that no individual parts of the injector are serviced. This injector is precision assembled by a machine, and replacing individual injector components would result in unacceptable performance problems or injector failures.
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SPACER
SLEEVE
ARMATURE VALVE SOLENOID
VALVE BODY
SHIM BARREL
PISTON
ADAPTER
UNIT INJECTOR COMPONENTS
WASHER UPPER FUEL SEAL
PLUNGER FUEL INLET CHECK VALVE
PIN SLEEVE SPACER LOWER FUEL SEAL CHECK NOZZLE
58 • Injector component parts
This slide shows the component parts in the three basic groups discussed previously. The valve body has three parts (body, adaptor and spacer) which are assembled with great precision. Any damage sustained in the valve body area during installation or removal will cause an injector failure.
NOTICE The correct injector removal procedures and tooling specified in the service manual must always be used. Any leverage applied below the valve body can cause deformation of the poppet valve bore and possible injector failure.
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INJECTOR INSTALLATION ALLEN SCREWS HORIZONTAL BOLTS
INJECTOR CLAMP
JUMPER TUBE INJECTOR OIL ADAPTOR
VERTICAL BOLTS
59 Injector Removal and Installation The correct procedures for injector removal and installation must be followed to avoid strain on the injector and hydraulic leaks in the jumper tube area. The three mating surfaces of the jumper tube, oil adaptor and injector must be aligned before final torque is applied. INSTRUCTOR NOTE : At this time, it is recommended that the injector removal and installation procedures be demonstrated. Emphasis should be placed on the use of the correct puller during removal (rather than a pry bar, which could result in injector damage). Also, disassemble a used injector to identify the various components shown on this slide.
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• Injector assembly and installation
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This portion of the assembly procedure ensures that all mating and sealing faces are flush and in complete contact before tightening the bolts. 1. Clean the faces of the injector and the injector sleeve and install new o-rings. 2. Lubricate the o-rings with oil and insert the injector in the injector sleeve. 3. Visually align the injector with the flat surface parallel to the centerline of the engine. 4. Position the injector clamp on the injector and tighten the bolt to 47 ± 9 N•m (35 ± 7 lb. ft.). 5. Install new seals on the jumper tube and rocker arm base. 6. Place the injector oil adaptor and jumper tube in position. 7. Install the allen screws and hex head bolts finger tight. If the injector oil adaptor was previously installed on the injector, loosen the allen screws.
The objective at this point in the procedure is to bring all the mating faces into complete contact and alignment before starting the final torque procedure. Failure to align the components will put a strain on the injector which will then distort the poppet valve and barrel bores. These components operate with a clearance of 5 microns because of the high injection and hydraulic pressures. Therefore, even a small amount of distortion will cause a seizure. Additionally, some misalignment could cause combustion gases to enter the supply system.
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• Injector installation torque sequence
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After all the mating surfaces are aligned, the torquing procedure can be performed: 1. Tighten the allen screws and hex head bolts finger tight or just sufficiently to bring the mating surfaces together and into alignment. 2. Apply an initial torque to the vertical hex head bolts of 5 ± 3 N•m (4 ± 2 lb. ft.). 3. Apply an initial torque to the horizontal hex head bolts of 5 ± 3 N•m (4 ± 2 lb. ft.). 4. Apply an initial torque to the allen screws of 1 ± 0.2 N•m (10 ± 2 lb. in.). 5. Final torque the vertical hex head bolts to 47 ± 9 N•m (35 ± 7 lb. ft.). 6. Final torque the horizontal hex head bolts to 47 ± 9 N•m (35 ± 7 lb. ft.). 7. Final torque the allen screws to 12 ± 3 N•m (9 ± 2 lb. ft.). 8. Check the system for leaks (crank with injection disabled). Then, check the hydraulic pressure (compare with desired pressure).
A number of possibilities for leaks can exist. Oil under high pressure may leak from the jumper tube joints or from the injector valve body exhaust port. Fuel could leak from the upper seal on the injector. Also, combustion gas can possibly leak from the base of the injector. If air has entered the fuel supply system, multiple injectors on one bank may malfunction. If the above procedure was not followed, air could enter past the lower o-ring seal. If this condition occurs, remove the injector and check for carbon below the lower o-ring seal. Replace the seal and perform the torque sequence. Air in the system may be detected by lightly touching the flexible return line and checking for extreme pulsations or pressure spikes felt through the line. As an alternative, install a sight glass in each return line, run the engine and check for air. Combustion gas leakage will usually affect the injector with the leak followed by the injectors downstream (toward the rear) of the leak. In conclusion, the system is reliable. However, failure to follow these procedures may cause malfunctions.
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VALVE BODY GROUP SOLENOID DE-ENERGIZED
SOLENOID ENERGIZED
POPPET VALVE CLOSED
POPPET VALVE OPEN
POPPET VALVE
SOLENOID
ARMATURE
INLET VALVE SEAT
EXHAUST VALVE SEAT
POPPET SPRING
ARMATURE SCREW
60 Injection Sequence • Solenoid de-energized
When the solenoid is de-energized, the poppet valve is held on its inlet (left) seat by the poppet spring. The poppet valve is connected to the armature by the armature screw. When the poppet is closed, the inlet seat prevents high pressure oil from entering the injector. The exhaust poppet seat is open, connecting the intensifier piston cavity to the atmosphere.
• Solenoid energized
Based on input signals from the various electronic sensors, the ECM calculates the quantity and timing of fuel to be delivered by the injector to the combustion chamber. At the appropriate time, the ECM sends an electrical current to the injector solenoid.
• Oil flows to intensifier piston
The solenoid develops a magnetic force which attracts the armature and shifts the poppet valve. The poppet valve moves against the spring force, opens the inlet seat and closes the exhaust (right) seat. Hydraulic pressure oil from the supply manifold is directed through the jumper tube to the top of the intensifier piston.
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SUPPLY OIL
INTENSIFIER PISTON
BARREL GROUP FUEL PRESSURE INCREASE BARREL
PLUNGER
FUEL INLET CHECK VALVE REVERSE FLOW CHECK VALVE
FUEL FROM TRANSFER PUMP
FUEL TO NOZZLE
61 • Plunger moves down • Pressurizes fuel below plunger
• Pressure intensification
Supply oil flow from the poppet valve causes the intensifier piston and the fuel plunger to move downward. The displacement of the plunger pressurizes the fuel trapped between the plunger face and the nozzle check seat. NOTE: The intensifier piston has almost seven times the area of the fuel plunger. When the hydraulic circuit is supplying a pressure of 21000 kPa (3000 psi), approximately 145000 kPa (21000 psi) will be generated below the fuel plunger.
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NOZZLE GROUP
REVERSE FLOW CHECK VALVE
VIEW OF STOP PLATE & REVERSE FLOW CHECK VALVE
CHECK VALVE FUEL ATOMIZATION
62 • Fuel atomization
When the trapped pressure exceeds the nozzle valve opening pressure (VOP), typically 31000 kPa (4500 psi), the check valve lifts, and fuel flows through the holes in the nozzle into the combustion chamber. At the end of injection, the nozzle check valve closes at approximately 21000 kPa (3000 psi). The reverse flow check valve is used to prevent combustion induced gas flow from entering the nozzle area. The nozzle of the injector is very similar to the EUI unit injector. Six orifices, each with a diameter of 0.252 mm (.010 in.), are arranged at an angle of 140 degrees.
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VALVE BODY GROUP SOLENOID DE-ENERGIZED POPPET VALVE
SOLENOID
ARMATURE
INLET VALVE SEAT EXHAUST VALVE SEAT
63 • End of injection
• Solenoid de-energized
• Poppet valve closes
The end of injection is accomplished by shutting off the current from the ECM to the injector solenoid. The resulting loss of magnetic force on the armature allows the return spring force to shift the poppet valve off the exhaust seat. The poppet returns to the inlet seat in the valve body, blocks the flow from the hydraulic oil supply, and simultaneously fully opens the exhaust valve seat. This action vents the injector internal hydraulic circuit below the valve cover.
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SPACER
SLEEVE VALVE
ARMATURE SOLENOID BODY SHIM BARREL ADAPTER
PISTON
WASHER
UNIT INJECTOR END OF INJECTION
PLUNGER BALL
PIN SLEEVE SPACER
CHECK NOZZLE
64 • End of injection • Intensifier piston moves up
• Nozzle check valve closes
When vented, the intensifier piston and fuel plunger are pushed upward by the plunger return spring force until the intensifier piston contacts the valve body. This upward displacement of the intensifier piston vents spent oil from the injector below the valve cover. Retraction of the fuel plunger decreases the pressure in the fuel chamber below the plunger, which permits the nozzle check valve to close when the pressure in the nozzle drops below the valve closing pressure (VCP) of approximately 21000 kPa (3000 psi).
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BARREL
PISTON
WASHER
BARREL GROUP REFILLING THE BARREL PLUNGER FUEL INLET CHECK VALVE FUEL EDGE FILTER
PIN SLEEVE
SPACER
NOZZLE CHECK VALVE
NOZZLE
65 • Barrel refilling
As the plunger continues to retract, the pressure below the plunger decreases below the fuel supply gallery pressure. The fuel inlet check valve then opens, allowing fuel to pass through the edge filter (next slide) to the supply gallery to refill the injector for the next injection sequence.
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EDGE FILTER FUEL INLET CHECK VALVE REVERSE FLOW CHECK VALVE FUEL INLET
FUEL INLET
EDGE FILTER
66 • Fuel edge filter
Note the location of the fuel edge filter. The edge filter is formed by two flat parallel surfaces that are approximately 130 microns apart. These surfaces trap and break down particles which might be big enough to plug the nozzle orifices.
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PRIME INJECTION RATE SHAPING
PRIME = PRE-INJECTION METERING
INJECTION RATE
START OF INJECTION
0
1
DURATION
2
3
4
5
TIME (MILLISECONDS)
67 • Injection rate shaping
• Low emission levels
• PRIME
Another feature used in the injector for 3408E/3412E applications is an injection rate shaping device. Rate shaping refers to tailoring the way fuel is delivered to the engine to obtain a desirable result. In the 3408E/3412E application, rate shaping reduces the quantity of fuel delivered to the combustion chamber during the ignition delay period (i.e. the time between the start of injection and start of combustion) to levels which produce low engine combustion noise and low emissions. The device used to create rate shaping is known as PRIME, an abbreviation for PRe-Injection MEtering. This device is basically a controlled spill port which serves to limit the amount of fuel delivered to the combustion chamber during the initial 25% displacement of the fuel plunger. This metering action produces the desired reduction of fuel delivery during the ignition delay period.
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BARREL GROUP OIL FLOW
PRIME RATE SHAPING
BARREL
PLUNGER
PRIME RATE SHAPING PASSAGE
SPILL PORT
CROSS SECTION OF PLUNGER FUEL TO NOZZLE GROUP
START OF INJECTION
PRESSURE DROP
FINAL PRESSURE INCREASE
68 • Injection rate shaping
1. Start of injection
2. Pressure drop
3. Final increase
• Benefits
This slide shows the three stages in PRIME rate shaping. 1. Injection pressure starts to increase and causes the initial movement of the plunger. 2. When the prime rate shaping passage on the plunger is passing the spill port in the barrel, pressure decreases below VCP as pressurized fuel leaks through the passage in the plunger into the spill port. At this time, nozzle flow momentarily decreases. 3. As the plunger continues downward, the PRIME rate passage passes the spill port and pressure will again increase, causing injection to resume. This feature reduces emissions, smoke and noise. It also provides a smoother combustion cycle and reduces wear on the cylinder components.
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INTENSIFIER PISTON INTENSIFIER PISTON SEAL
BARREL GROUP VENTING INTERNAL LEAKS
BARREL
VENTING CHECK VALVE
69
• Internal leakage
During the normal injection cycle, the pressure of the oil supplied to the top of the intensifier piston can increase to 22800 kPa (3300 psi). A seal is installed to minimize leakage past the piston. Some oil which is necessary for lubrication of the intensifier piston may pass the seal and settle momentarily below the piston. Also, a small amount of fuel may leak past the plunger and barrel. This fuel will settle momentarily in the cavity below the intensifier piston.
• Fluids are vented to pump inlet
If the fluids which accumulate below the piston are not vented, a hydraulic lock could occur. As the piston moves down, the fuel is ejected past the barrel ball check valve to the low pressure inlet. The check valve then closes during the plunger and piston upstroke.
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INJECTOR CHECK VALVES FUEL INLET CHECK VALVE
BARREL GROUP
NOZZLE GROUP VENTING CHECK VALVE
REVERSE FLOW CHECK VALVE
NOZZLE CHECK VALVE
FUEL ATOMIZATION
70 • Injector check valves:
Four check valves are installed in the injector. Three check valves are installed in the Barrel Group and one is installed in the Nozzle Group.
- Fuel inlet
The Fuel Inlet Check Valve allows fuel to fill the barrel below the plunger, but closes as the plunger moves down and pressure increases.
- Barrel
The Venting Check Valve vents fluids from below the intensifier piston.
- Reverse flow
The Reverse Flow Check Valve prevents combustion gasses from flowing back through the injector from the nozzle.
- Nozzle
The Nozzle Check Valve controls valve opening pressure by preventing the flow of fuel through the nozzle holes until sufficient pressure is available to lift the valve from its seat.
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INJECTION PRESSURE
HYDRAULIC INJECTION PRESSURE CONTROL
HEUI
MECHANICALLY ACTUATED FUEL SYSTEM
IDLE
PEAK TORQUE
RATED
ENGINE SPEED
71 HYDRAULIC SYSTEM • Hydraulic pressure control
The desired hydraulic actuation pressure for fuel injection can be controlled independent of engine speed. Many combinations of on-time and hydraulic operating pressure exist which can result in a specific quantity of fuel per injector stroke being delivered to the combustion chamber. This characteristic is useful when tuning the engine to optimize performance, response, emissions, and other parameters. This feature makes the HEUI system superior; injection pressure can reach its maximum value regardless of engine speed. Maximum injection pressure is normally required at full torque speed. This characteristic contrasts with pump and line systems where pressure is proportional to engine speed.
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72 Hydraulic Supply Pump Group • Variable displacement piston pump
The 3408E/3412E Hydraulic Supply Pump Group is a variable displacement, axial piston pump similar to those used in many machine hydraulic systems. The pump features a nine piston rotating group and variable displacement control. The pump is driven by the engine timing gears at 1.167 times engine speed and produces 59 L/min. (15.5 gpm) at rated engine speed.
• Cold start oil reservoir
Low pressure oil from the engine lubricating pump is supplied to the inlet of the pump Cold Start Oil Reservoir. The purpose of the reservoir is to keep the system primed during cool down. During cold starting conditions, this volume of oil helps to shorten start times. The lubrication system oil pressure and hydraulic temperature sensors are located in the reservoir.
• Serviceable parts
The Hydraulic Supply Pump Group contains the following serviceable parts: - Transfer Pump - Reverse Flow Check Valves - Pump Control Valve - Compensator Valve Block
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3 1
2
73 • Hydraulic supply pump mounting adapter 1. Pump drive splines 2. Alignment bolt hole 3. Atmospheric pressure sensor location
The Hydraulic Supply Pump group is mounted on the adapter shown on the slide. The pump drive shaft engages in the drive splines (1). A large bolt is installed in the hole (2) in the adaptor base to provide good alignment between the adaptor and the engine block. Note the location of the Atmospheric Pressure Sensor (3) in the housing. The Atmospheric Pressure sensor is vented to the atmosphere below the housing. The housing contains a foam plug to prevent the entry of dirt into the sensor.
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PRIMING PORT
COMPENSATOR VALVE
HEUI PUMP
VALVE BASE
ORIFICE DRAIN PASSAGE
TRANSFER PUMP
RESERVOIR
SWASHPLATE
74 • Pump priming
Priming the pump after replacement is extremely important to prevent slipper pad overheating. Pump failure or damage will occur due to lack of lubrication if the case is not filled during replacement.
• Priming port
The priming port is located adjacent to the inlet tube (not shown) and is the rearmost of the two plugs. The front plug is the case drain passage and is vented over the pump drive gears. Therefore, the front plug cannot be used for priming.
• Case drain orifice
A .50 mm (.020 in.) orifice is located between the fill port line and the case drain line. This orifice allows a continuous flow from the case to the drain circuit for lubrication, cooling and venting of air from the reservoir. The procedure to prime the Hydraulic Supply Pump case is:
• Priming procedure
1. Remove the plug from the priming port. 2. Fill the compartment with oil and replace the plug. 3. Fill the reservoir with oil (if the machine is not equipped with pre-lube).
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75 • Fuel transfer pump (arrow)
The fuel transfer pump (arrow) is driven by a coupling that connects the end of the high pressure supply pump drive shaft to the transfer pump input shaft. This gear pump has an integral relief valve set to open at 620 to 760 kPa (90 to 110 psi). This valve does not normally operate because the pressure regulating valve (next slide) is controlling the pressure. Fuel is drawn from the tank to the combined primary fuel filter/water separator. The fuel then passes through the ECM and the secondary fuel filter to the fluid manifold and the injectors.
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76 • Pressure regulating valve
Fuel system pressure is controlled by the Pressure Regulating Valve. This valve regulates pressure between 310 to 415 kPa (45 to 60 psi). The valve is located downstream of the fluid manifold fuel passages and the injectors. Fuel which passes through the valve is returned to the fuel tank. The fuel lines from both fuel passages in the manifolds are joined at the regulating valve.
• Fuel pressure test plug (arrow)
Fuel pressure can be checked by removing the plug (arrow) and connecting a gauge.
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COOL DOWN BYPASS CIRCUIT TO LUBE SYSTEM
.020 IN. ORIFICE
HEUI HYDRAULIC TEMPERATURE SENSOR
DRAIN COLD START OIL RESERVOIR
OIL FILTER
FLUID MANIFOLD HYDRAULIC PASSAGE
OIL PRESSURE SENSOR COOL DOWN CIRCUIT
HYDRAULIC SUPPLY PUMP GROUP
FUEL TEMPERATURE SENSOR
HYDRAULIC PRESSURE SENSOR
FLUID MANIFOLD HYDRAULIC PASSAGE PUMP CONTROL VALVE
HEUI ECM
OIL COOLER FUEL TRANSFER PUMP
LUBE OIL PUMP
SECONDARY FUEL FILTER
PRESSURE REGULATING VALVE
PRIMARY FUEL FILTER WATER SEPARATOR OIL SUMP
FUEL TANK
77 • Cold start oil reservoir
The Cold Start Oil Reservoir is located above the Hydraulic Supply Pump Group. The Hydraulic (Oil) Temperature and Lube Oil Pressure Sensors are located at the top of the reservoir. When the engine is shut down and oil in the supply manifolds cools and contracts, oil from the reservoir flows through the cool down circuit to the manifolds. This design prevents the formation of air bubbles in the hydraulic supply manifolds during cooling to provide fast starting and smooth running. A 0.50 mm (.020 in.) drilled passage in the reservoir allows the air to be vented through the case drain after start-up.
• Reverse flow check valves
The Reverse Flow Check Valves prevent hydraulic surges between the oil supply passages and are used to maintain stable pressures. The valves are shown on the next slide.
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78 This view shows the rear of the hydraulic supply pump with the aftercooler removed from the engine. • Reverse flow check valves (arrows)
The Reverse Flow Check Valves (arrows) are located at the rear of the pump group to the right of the transfer pump. The high pressure lines to the manifolds are connected to the check valves.
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REVERSE FLOW CHECK VALVE
SEAT (END VIEW)
FROM PUMP
TO INJECTORS
FITTING
VALVE BLOCK
SPRING
CHECK
SEAT
79 • Reverse flow check valve
The hydraulic supply pump group has two outlet ports, each connected by steel tubes to a hydraulic supply manifold. An integral reverse flow check valve is located in each outlet port.
• Check valves block pressure surges from injectors
This view shows that pressure surges travelling back from the injectors toward the pump will cause the check valve to close and block any interference between the banks. In normal operation, the valve will oscillate at high frequency as it blocks the pressure surges. The valve check fits loosely on the shaft to allow oil flow from the reservoir during the cooling process. If the check valves were not in the system, pressure surges between the banks would cause erratic operation of the injectors by adversely affecting timing. The pressure surge causes the poppet valves to open prematurely. This condition would start fuel injection earlier than normal, thereby advancing the timing.
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1
4 2 6
5
3
80 • Pump components:
This cutaway view of the Hydraulic Supply Pump Group shows the following components:
1. Cold start reservoir
Cold Start Oil Reservoir (1)
2. Swashplate
Swashplate (2)
3. Swashplate pivot
Swashplate Pivot (3)
4. Displacement control piston
Displacement Control Piston (4)
5. Pump piston
Pump Pistons (5, one of seven shown)
6. Check valves
Check Valves (6)
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1
2 3 4 5
11 6
7
9 8 10
81 • Valve components: 1. Compensator valve assembly 2. Pressure limiter spool
This cutaway view shows the compensator valve assembly and the pump control valve. Note the following components which will be referred to in the presentation: Compensator Valve Assembly (1) Pressure Limiter Spool (2)
3. Load sensing spool
Load Sensing Spool (3)
4. Check valve
Check Valve (4)
5. Valve base
Valve base (5)
• Oil passages: 6. Oil supply from pump 7. Pressure limiter to case drain 8. To displacement control piston 9. Pump control valve to case drain
Oil Passages: Oil supply from pump (6) Pressure Limiter to Case Drain (7) To Displacement Control Piston (8) Pump Control Valve to Case Drain (9) Transfer Pump Drive and Mounting (10) Pump Control Valve (11)
• Pump components: 10. Transfer pump drive and mounting 11. Pump control valve
INSTRUCTOR NOTE: The Compensator Valve is an emissions device and should not be adjusted.
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3408E/3412E HEUI FUEL SYSTEM HYDRAULIC SYSTEM OPERATION
TO LUBE SYSTEM
HEUI HYDRAULIC TEMPERATURE SENSOR COLD START OIL RESERVOIR
OIL FILTER
COOL DOWN CIRCUIT
HYDRAULIC SUPPLY PUMP GROUP
OIL COOLER
FLUID MANIFOLD HYDRAULIC PASSAGE
OIL PRESSURE SENSOR
HYDRAULIC PRESSURE SENSOR
FUEL TEMPERATURE SENSOR
FLUID MANIFOLD HYDRAULIC PASSAGE PUMP CONTROL VALVE FUEL TRANSFER PUMP
LUBE OIL PUMP
HEUI
ECM
SECONDARY FUEL FILTER
PRESSURE REGULATING VALVE
PRIMARY FUEL FILTER OIL SUMP
FUEL TANK
82 System Operation • Hydraulic supply pump circuit
As stated earlier, the Hydraulic Supply Pump Group combines the functions of the high pressure oil pump, the fuel transfer pump, and the pump control valve into a single unit. The function of the Hydraulic Supply Pump Group is to provide the required oil flow at the desired pressure to operate the injectors, provide the supply of low pressure fuel required for refilling the injectors after each injection, and for ECM cooling. As the oil is supplied by the pump rotating group, the pressure is raised from the reservoir level of approximately 415 kPa (60 psi) to the pressure required for injector operation. Depending on the engine rating, the operating conditions, and the engine mapping characteristics, this pressure is controlled between 5000 and 22800 kPa (725 and 3300 psi).
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HEUI HYDRAULIC CONTROL SYSTEM START-UP TO LUBE SYSTEM
COLD START RESERVIOR
DISPLACEMENT CONTROL PISTON
TO LEFT OIL MANIFOLD
CHECK VALVE SUPPLY PUMP
SOLENOID (ENERGIZED)
OIL SUMP
TO RIGHT OIL MANIFOLD
PRESSURE LIMITER SPOOL
LOAD SENSING SPOOL
PUMP CONTROL VALVE PUMP CASE DRAIN
83 • Conditions during START-UP
The displacement of the pump is controlled to maintain the desired operating pressure at the flow rate required by the injectors. The displacement is regulated by an electro-hydraulic control.
• Displacement varied by changing swashplate angle
Displacement of the pump is varied by pivoting the swashplate from 0 degrees to a maximum angle of 15.5 degrees. When the engine is not running, the swashplate is at the maximum angle. During operation, the displacement control piston adjusts the swashplate position to meet the system flow demand.
• Swashplate at full displacement during start-up
During initial cranking, the swashplate is at full displacement until the supply pressure increases to 6200 kPa (900 psi). The spring at the end of the load sensing spool regulates this pressure. Then, the specification programmed into the ECM for normal cranking will override this pressure. Until this point, the control valve solenoid is fully energized for the pressure increase.
• Pump control valve solenoid energized
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COMPENSATOR ASSEMBLY START-UP PRESSURE LIMITER SPOOL ORIFICE PUMP CONTROL VALVE
LOAD SENSING SPOOL
CHECK VALVE
FROM DISPLACEMENT CONTROL PISTON
DRAIN ORIFICE TO CASE DRAIN TO CASE DRAIN REVERSE FLOW CHECK VALVES
84 • Compensator valve conditions during START-UP
During START-UP, pressure from the pump enters the compensator assembly. The Pump Control Valve is energized for quick pressure build-up.
• Displacement control piston vented to case drain
Pressure is felt at both ends of the Load Sensing Spool. The spool is shifted to the right and oil from the Displacement Control Piston is vented to case drain. The swashplate is at maximum angle. The drain orifice below the Pump Control Valve provides a small amount of restriction to improve valve stability.
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HEUI HYDRAULIC CONTROL SYSTEM DESTROKE TO LUBE SYSTEM
TO LEFT OIL MANIFOLD
COLD START RESERVIOR
TO RIGHT OIL MANIFOLD
DISPLACEMENT CONTROL PISTON
CHECK VALVE SUPPLY PUMP
SOLENOID (DE-ENERGIZED)
OIL SUMP
PRESSURE LIMITER SPOOL
LOAD SENSING SPOOL
PUMP CONTROL VALVE PUMP CASE DRAIN
85 • Conditions during DESTROKE • Pump control valve solenoid de-energized • Pump control valve changes pump displacement
After the engine starts and pressure increases, the ECM will signal the control valve to match the actual with the desired pressure by momentarily de-energizing and then regulating the current flow to the pump control valve solenoid. The decrease in current applied to the pump control valve solenoid lowers the pressure required to initiate flow through the pump control valve. This lower cracking pressure on the pump control valve creates a force imbalance on the load sensing spool, causing the spool to move toward the spring end of the compensator. This spool motion connects the displacement control piston to pump output flow, allowing the swashplate to decrease the displacement of the pump. The decreased displacement lowers the pump output to the pressure level required by the ECM.
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COMPENSATOR ASSEMBLY DESTROKE
PUMP CONTROL VALVE
PRESSURE LIMITER SPOOL ORIFICE
LOAD SENSING SPOOL CHECK VALVE
TO DISPLACEMENT CONTROL PISTON
DRAIN ORIFICE
TO CASE DRAIN
86 • Compensator valve conditions during DESTROKE
During DESTROKE, the ECM momentarily de-energizes the Pump Control Valve causing a pressure drop in the spring chamber of the Load Sensing Spool.
• Displacement control piston pressurized
Unbalanced pressures force the spool to the left, allowing the oil to enter the Displacement Control Piston and move the swashplate toward minimum angle.
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HEUI HYDRAULIC CONTROL SYSTEM UPSTROKE TO LUBE SYSTEM
COLD START RESERVIOR
DISPLACEMENT CONTROL PISTON
TO LEFT OIL MANIFOLD
CHECK VALVE SUPPLY PUMP
SOLENOID (ENERGIZED)
TO RIGHT OIL MANIFOLD
PRESSURE LIMITER SPOOL
LOAD SENSING SPOOL
OIL SUMP PUMP CONTROL VALVE PUMP CASE DRAIN
87 • Conditions during UPSTROKE
As the load on the engine increases and higher pressure is required, the ECM will signal the control valve to increase pressure by increasing the current flow to the pump control valve solenoid.
• Pump control valve energized
The increase in current applied to the pump control valve solenoid raises the pressure setting of the pump control valve. This higher pressure at the pump control valve creates a force imbalance on the load sensing spool, causing the spool to move toward the supply signal line end of the compensator. This spool motion vents the displacement control piston to case drain, allowing the spring to move the swashplate to increase the displacement of the pump. The increased displacement raises the pump output to the desired pressure level required by the ECM.
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COMPENSATOR ASSEMBLY UPSTROKE
PUMP CONTROL VALVE
PRESSURE LIMITER SPOOL
ORIFICE LOAD SENSING SPOOL CHECK VALVE
FROM DISPLACEMENT CONTROL PISTON
DRAIN ORIFICE
TO CASE DRAIN
88 • Compensator valve positions during UPSTROKE
• Displacement control piston is drained
As the load is applied to the engine, the ECM increases current to the Pump Control Valve. Pressure is felt at both ends of the Load Sensing Spool. The spool moves to the right (due to spring force) and oil from the Displacement Control Piston is vented to case drain, which allows the swashplate to momentarily go to maximum angle and build pressure quickly.
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HEUI HYDRAULIC CONTROL SYSTEM PRESSURE LIMITER OPERATION TO LUBE SYSTEM
TO LEFT OIL MANIFOLD
COLD START RESERVIOR
TO RIGHT OIL MANIFOLD
DISPLACEMENT CONTROL PISTON
PRESSURE LIMITER SPOOL
SUPPLY PUMP SOLENOID (DE-ENERGIZED)
LOAD SENSING SPOOL
PLUGGED ORIFICE
OIL SUMP PUMP CONTROL VALVE PUMP CASE DRAIN
89 • Pressure limiter operation
If the load sensing spool or pump control valve sticks or otherwise malfunctions to create higher than desired operating pressures, the maximum pressure limiter spool is utilized. In this schematic, a plugged orifice is simulated. (This example represents an actual condition which was caused by debris being introduced during a field replacement of the compensator valve.) The Pressure Limiter Spool directs pump outlet flow to the displacement control piston and reduces the stroke of the pump if the system pressure exceeds 25600 kPa (3700 psi).
• Check engine lamp indicates the fault
During these conditions, the pump will develop 24800 to 25600 kPa (3600 to 3700 psi) maximum pressure, regardless of the desired hydraulic pressure. The Check Engine Lamp will be ON, indicating a fault.
• Pump control valve test
A Pump Control Valve Test will verify the control valve operation. This test enables the technician to manually ramp the pressure up and down using the ET service tool. This procedure will also be useful when evaluating the condition of the hydraulic system.
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COMPENSATOR ASSEMBLY PRESSURE LIMITER OPERATION PRESSURE LIMITER SPOOL PUMP CONTROL VALVE
ORIFICE
LOAD SENSING SPOOL CHECK VALVE
TO DISPLACEMENT CONTROL PISTON
PLUGGED ORIFICE DRAIN ORIFICE
TO CASE DRAIN
90 • Pressure limiter operation • Pressure limiter directs pressure to control piston
If the supply pressure exceeds 25600 kPa (3700 psi), the force acts on the Pressure Limiter Spool and shifts it to the left. This movement compresses the spring and allows oil to unseat the check valve and pressurize the displacement control piston. The swashplate moves to minimum angle to decrease flow and limit system pressure.
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PUMP CONTROL VALVE NO CURRENT FLOW COIL ASSEMBLY
STOP
POPPET VALVE
ADAPTER SEAL
SEAT CAGE
FROM LOAD SENSING SPOOL VALVE
STATOR EDGE FILTER
SPRING RETAINER
ARMATURE
SOLENOID
PIN
SHELL
RING
TO CASE DRAIN
VALVE BLOCK
91 • Pump control valve
The pump control valve is mounted on the compensator control assembly which contains the load sensing spool and the pressure limiter. In this slide, the pump control valve is open, allowing pressure to vent to case drain.
• Flow controlled by compensator and pump control valve
Flow to and from the displacement control piston is determined by the compensator control assembly and the pump control valve. The compensator control assembly senses pump output pressure through a pilot pressure signal line. The pump control valve varies the pressure to the displacement control piston by varying the pressure on one end of the load sensing spool valve. The load sensing spool directs oil to and from the displacement control piston. The spool has a hole through its center, which allows pilot pressure to reach both ends of the spool. The spring force on the load sensing spool is adjusted at the factory. The pump will develop 5000 kPa (725 psi) with the pump control solenoid valve disconnected while cranking the engine with the injectors disabled.
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PUMP CONTROL VALVE HIGH CURRENT FLOW COIL ASSEMBLY
STOP
POPPET VALVE
ADAPTER SEAL
SEAT CAGE
FROM LOAD SENSING SPOOL VALVE
STATOR EDGE FILTER
SPRING RETAINER
ARMATURE
SOLENOID
PIN
SHELL
RING
CASE DRAIN
VALVE BLOCK
92 • Pump control valve • High current flow equals high pressure
The pressure level in the hydraulic operating supply is monitored by a hydraulic pressure sensor. When the hydraulic pressure is less than desired (as determined by the ECM), the current level applied to the pump control valve solenoid is increased. The increase in current to the solenoid raises the pressure required to initiate flow through the pump control valve. This higher cracking pressure for the pump control valve creates a force imbalance on the load sensing spool, causing the load sensing spool to move toward the supply signal line end of the spool. This spool motion vents the displacement control piston to pump case drain, allowing the swashplate to increase displacement of the pump. The increased displacement raises the hydraulic output to the rate required by the ECM for the injectors.
➥
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INSTRUCTOR NOTE: To reinforce this presentation, the following tasks may be demonstrated on an engine: Hydraulic pump priming Remove and install a pump control valve and the compensator valve assembly. Check the following using the status screen: - Desired hydraulic pressure - System hydraulic oil pressure - System hydraulic oil temperature - Percentage current to pump control valve Using the ET Injection Actuation Pressure Test, check the pump and pump control valve operation, and check for correct pressures throughout the range. Physically check for leaks externally and internally below the valve covers (injectors must be disabled during cranking with the valve covers removed).
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HEUI SYSTEM POWER SUPPLIES • ECM: 24 VOLTS • SPEED/TIMING SENSORS: 12.5 VOLTS • INJECTORS: 105 VOLTS • ANALOG SENSORS: 5 VOLTS • DIGITAL SENSORS: 8 VOLTS • PUMP CONTROL VALVE: 0 to 24 VOLTS
93 SYSTEM POWER SUPPLIES • Six system power supplies
The HEUI system has six power supplies with various voltages as shown. EXTERNAL POWER SUPPLY ECM power supply
24 Volts
INTERNAL POWER SUPPLIES Speed/Timing Sensor power supply
12.5 Volts
Injector power supply
105 Volts
Analog Sensor power supply
5 Volts
Digital Sensor power supply
8 Volts
Pump Control Valve power supply
0 to 24 Volts
The power supplies are described in detail in the following section.
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3408E/3412E HEUI SYSTEM ECM POWER SUPPLY COMPONENTS
8 OR 12 INJECTORS
ADEM II ELECTRONIC CONTROL MODULE (ECM)
ENGINE HARNESS
MACHINE HARNESS
DISCONNECT SWITCH
GROUND BOLT
15 AMP BREAKER
MAIN KEY POWER RELAY SWITCH
24 V
PUMP CONTROL VALVE MACHINE INTERFACE CONNECTOR
HYDRAULIC PRESSURE SENSOR PRIMARY SPEED/TIMING SENSOR
TDC SERVICE PROBE ACCESS
THROTTLE SENSOR
ACCELERATOR PEDAL
SECONDARY SPEED/TIMING SENSOR
THROTTLE BACK-UP, ELEVATED LOW IDLE ENABLE, AND GROUND LEVEL SHUTDOWN (2) SWITCHES TURBO INLET PRESSURE SENSOR
COOLANT TEMP. SENSOR
FAN CONTROL VALVE TURBO OUTLET PRESS. SENSOR FAN SPEED SENSOR FAN
ATMOSPHERIC PRESS. SENSOR CAT DATA LINK
ELECTRONIC SERVICE TOOL
OIL PRESSURE SENSOR
EPTC II TRANSMISSION CONTROL HYDRAULIC TEMP. SENSOR
AUTO RETARDER CONTROL
FUEL TEMPERATURE SENSOR INSTRUMENT PANEL
COOLANT FLOW SWITCH
94 ECM Power Supply • 24-Volt power supply
• Power supply components
The power supply to the ECM and the system is drawn from the 24-Volt machine battery. The principle components in this circuit are: - Battery - Key Start Switch - Main Power Relay - 15 Amp Breaker - Ground Bolt - ECM Connector (P1/JI) - Machine Interface Connector (J3/P3) If the supply voltage exceeds 32.5 Volts or is less than 9.0 Volts, a diagnostic code is logged. (See the Troubleshooting Guide for complete details on voltage event logging.) NOTE: The ground bolt is the only power supply component mounted on the engine.
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ECM POWER SUPPLY CIRCUIT
DISCONNECT SWITCH
ENGINE BLOCK GROUND BOLT
BATTERY P1 J1
(-) 24 VOLTS DC (+)
15 A CIRCUIT BREAKER 113-OR
1 2 26
229-BK-14 229-BK-14 150-RD-14 150-RD-14 113-OR
05 11 04 06 23
ECM (3408E/3412E) (-) BATTERY (-) BATTERY (+) BATTERY (+) BATTERY KEY SWITCH ON
P3 J3
10 AMP 112-PU 308-YL 117-RD
200-BK
105-RD
R C OFF S ON B ST KEY SWITCH
95 • ECM power supply circuit
This schematic shows the principle components for a typical power supply circuit. Battery voltage is normally connected to the ECM. However, an input from the key start switch turns the ECM on. The machine wiring harness can be bypassed for troubleshooting purposes. These steps are described in the Troubleshooting Procedure. The supply Voltage may be checked using the ET Status Screen display. NOTE: The power supply cables are paired to reduce resistance.
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SPEED/TIMING SENSOR POWER SUPPLY 12.5 ± 1 VOLTS SECONDARY SPEED/TIMING SENSOR (LH)
P44 J44 OR BK WH
A B C P2 J2
PRIMARY SPEED/TIMING SENSOR (RH)
ECM (3408E/3412E) P20 J20 OR BK WH
732-PK 996-GN 998-BR 999-WH F723-PK F724-PU
A B C
39 32 29 38 18 12
SECONDARY ENGINE SPEED +V TIMING DIGITAL RETURN PRIMARY ENGINE SPEED TIMING CAL + TIMING CAL -
P1 J1
96 Speed/Timing Sensor Power Supply • 12.5-Volt power supply
The Speed/Timing Sensors have a dedicated power supply. The ECM supplies 12.5 ± 1 Volts to the Primary and Secondary Speed/Timing Sensors. Connectors A and B send the common power supply to the sensors. The C wires transmit separate signals to the ECM. This power supply is not battery voltage, but is generated and regulated within 1.0 volt by the ECM. A power supply failure at the ECM will cause both sensors to fail and the engine will shut down since the sensors share the common power supply.
NOTICE Connecting another system or accessory to the Speed/Timing Sensor power supply can cause engine failure.
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INJECTOR WIRING SCHEMATIC J52/P52 SOLENOID 1 SOLENOID 3
1 2 3 4
P2 J2
ECM (3408/3412E)
A701-GY F726-YL A703-BR F726-YL
16 05 32
SOLENOID 1 POWER SOLENOID 1/3 RETURN SOLENOID 3 POWER
A702-PU F727-BU A704-GN F727-BU
40 11 34
SOLENOID 2 POWER SOLENOID 2/4 RETURN SOLENOID 4 POWER
A705-BU F728-BR A707-PU F728-BR
32 17 38
SOLENOID 5 POWER SOLENOID 5/7 RETURN SOLENOID 7 POWER
A706-GY F729-GN A708-BR F729-GN
28 21 22
SOLENOID 6 POWER SOLENOID 6/8 RETURN SOLENOID 8 POWER
A709-OR F730-GY A711-PU F730-GY
37 27 31
SOLENOID 9 POWER SOLENOID 9/11 RETURN SOLENOID 11 POWER
A710-GY F731-OR A712-BR F731-OR
18 33 12
SOLENOID 10 POWER SOLENOID 10/12 RETURN SOLENOID 12 POWER
J56/P56 SOLENOID 2 SOLENOID 4
1 2 3 4 J53/P53
SOLENOID 5 SOLENOID 7
1 2 3 4 J57/P57
SOLENOID 6 SOLENOID 8
1 2 3 4 J54/P54
SOLENOID 9 SOLENOID 11
1 2 3 4 J58/P58
SOLENOID 10 SOLENOID 12
1 2 3 4
97 Injector Power Supplies • 105-Volt power supply
The injectors are supplied with power from the ECM at 105 Volts. For this reason, precautions must be observed when performing maintenance around the valve covers. On the 3412E, two separate power supplies are used for the injectors. If a failure occurs, only one bank of injectors could have failed. (On the 3408E, only one of the power supplies is used.) If an open or a short occurs in the injector circuit, the ECM will disable that injector. The ECM will periodically try to actuate that injector to determine if the fault is still present and will disconnect or reconnect the injector as appropriate.
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J21 P21
ENGINE COOLANT TEMPERATURE SENSOR
+V ANALOG ANALOG RETURN SIGNAL
A B C
ENGINE OIL PRESSURE SENSOR
+V ANALOG ANALOG RETURN SIGNAL
P22 J22 A B C
TURBO OUTLET PRESSURE SENSOR
+V ANALOG ANALOG RETURN SIGNAL
P23 J23 A B C
P1 J1 36 30
ANALOG SENSOR POWER SUPPLY
P25 J25 +V ANALOG ANALOG RETURN SIGNAL
A B C
ATMOSPHERIC PRESSURE SENSOR
+V ANALOG ANALOG RETURN SIGNAL
P27 J27 A B C
HYDRAULIC PRESSURE SENSOR
+V ANALOG ANALOG RETURN SIGNAL
P45 J45 A B C
FUEL TEMPERATURE SENSOR
+V ANALOG ANALOG RETURN SIGNAL
P43 J43 A B C
HYDRAULIC OIL TEMPERATURE SENSOR
+V ANALOG ANALOG RETURN SIGNAL
TURBO INLET PRESSURE SENSOR
ECM (3408E/3412E HEUI) +V ANALOG SUPPLY ANALOG RETURN
5 ± 0.2 VOLTS
P51 J51 A B C
98 Analog Sensor Power Supply • Provides power to all analog sensors
The Analog Sensor Power Supply provides power to all the analog sensors (pressure and temperature sensors).
• 5-Volt power supply
The ECM supplies 5.0 ± 0.2 Volts DC (Analog Supply) through the J1/P1 connector to each sensor. A power supply failure will cause all analog sensors to appear to fail. The power supply is protected against short circuits, which means that a short in a sensor or a wiring harness will not cause damage to the ECM.
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THROTTLE POSITION SENSOR +V DIGITAL DIGITAL RETURN SIGNAL
FAN SPEED SENSOR +V DIGITAL DIGITAL RETURN SIGNAL
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J35 P35
P1 J1
A B C
29 35
ECM (3408E/3412E HEUI) + V DIGITAL SUPPLY - V DIGITAL RETURN
DIGITAL SENSOR POWER SUPPLY 8 ± 0.5 VOLTS
P84 J84 A B C
99 Digital Sensor Power Supply • 8-Volt power supply
The ECM supplies power at 8 ± 0.5 Volts through the J1/P1 connector to the following circuits: - Throttle Position Sensor - Fan Speed Sensor (if installed) - Exhaust Temperature Sensor (may be installed on high performance industrial engines) The power supply is protected against short circuits, which means that a short in a sensor will not cause damage to the ECM.
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PUMP CONTROL VALVE POWER SUPPLY 0 to 24 VOLTS PWM 0 to 800 mAmps PUMP CONTROL VALVE SUPPLY RETURN
J46 P46
P2 J2
A B
29 35
ECM (3408E/3412E HEUI) + SUPPLY - RETURN
100 Pump Control Valve Power Supply The ECM supplies a PWM signal of 0 to 24 Volts (PWM) and 0 to 800 mA through the J2/P2 connector to the Pump Control Valve. • 0 to 24 Volts digital power supply
The control valve and power supply can be tested on the engine using ET and the Hydraulic Injection Actuation Pressure Test. Using the test, the pressure can be adjusted manually with the ET service tool from minimum to maximum. Therefore, this function can be used to verify the operation of the control valve, the power supply from the ECM and the hydraulic system.
• Injection actuation pressure test
When using the test, the pressure (expressed as a percentage of maximum) can be raised in increments of 1% up to 100%. The maximum value can only be reached when there is a leak in the system and the pump is at maximum displacement to make up for the pressure loss. Otherwise, the pressure may only reach a maximum of 49%. The minimum pressure is a function of the spring setting of the Compensator Valve. (This valve is an emission control and should not be adjusted.)
➥
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The service tool status screen can be used to show the percentage of the current being used. This measurement can be used in conjunction with the desired and actual hydraulic pressures to check the complete system operation. The Pump Control Valve uses a digital power supply because a PWM current is more easily regulated. Also, modulating the current at 500 Hz produces a vibrating effect on the poppet valve to prevent the valve from sticking. The poppet valve is kept in motion much like the rack in a hydra-mechanical governor. • Indicated voltages
NOTE: If the control valve voltage is read with an oscilloscope, it may show a peak of 24 Volts, while a Voltmeter may show up to 8 Volts rms. INSTRUCTOR NOTE: The following exercises will reinforce the material introduced in the preceding slides and will allow questions to be answered. During this exercise, a demonstration on an engine or a Training Aid should be performed showing: Open circuit in the ECM power supply Status screen supply voltage reading Opens and shorts in the Speed/Timing sensor power supply Opens and shorts in the analog and digital power supplies Status screen pressure and temperature readings with a fault in the sensor power supply Hydraulic Injection Actuation Pressure Test showing the percentage of current to the control valve
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ELECTRONIC SENSORS AND SYSTEMS
101 ELECTRONIC SENSORS AND SYSTEMS This section of the presentation covers the electronic sensors and related circuits in the 3408E and 3412E HEUI fuel system.
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HEUI SYSTEM
8 OR 12 INJECTORS
COMPONENT DIAGRAM ADEM II ELECTRONIC CONTROL MODULE (ECM)
ENGINE HARNESS
GROUND BOLT
DISCONNECT SWITCH
24 V
MACHINE HARNESS
TDC SERVICE PROBE ACCESS
MAIN 15 AMP POWER RELAY BREAKER
KEY SWITCH
MACHINE INTERFACE CONNECTOR
PRIMARY SPEED/TIMING SENSOR SECONDARY SPEED/TIMING SENSOR
102 Speed/Timing Sensors Two Speed/Timing Sensors are installed: a primary and a secondary. The Speed/Timing Sensors serve three basic functions in the system: • Three functions of the speed/timing sensor
- Engine speed detection - Engine timing detection - Cylinder and TDC identification
• Self-adjusting zero gap sensor
The Speed/Timing Sensors, which are mounted on the front housing below the timing gear wheel, are self-adjusting during installation. This type of sensor does not have a typical fixed air gap. The sensor is not in direct contact with the timing wheel but does run with a zero clearance.
➥
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• Speed/timing sensor failure modes
- 116 -
If a primary sensor failure occurs, the secondary sensor will provide the back-up automatically. A momentary change of engine sound is all that will be noticed as the changeover takes place. If the fault in the primary sensor is corrected, then the ECM will continue to use the secondary sensor until the engine is shut down and restarted. A subsequent speed/timing sensor failure will cause an engine shutdown. The sensor may be functionally checked by cranking the engine and observing the service tool status screen for engine rpm. A failure of either sensor will be indicated by the active fault screen on the service tool. An intermittent failure will be shown in the logged fault screen. Because both sensors share a common power supply, a power supply failure at the ECM will cause both sensors to fail.
• Sensor installation
The sensor head is extended prior to installation. The action of screwing in the sensor pushes the head back into the body after the head contacts the timing wheel. During installation, it is essential to check that the sensor head is not aligned with the wide slot in the timing wheel. If this condition occurs, the head will be severed when the engine is started, and some disassembly may be necessary to remove the debris. Also, the other sensor may be damaged by the debris.
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ANALOG SENSORS •
Hydraulic pressure
•
Coolant temperature
•
Atmospheric pressure
•
Turbocharger inlet pressure
•
Turbocharger outlet pressure
•
Lubrication oil pressure
•
Hydraulic temperature
•
Fuel temperature
103 Analog Sensors and Circuits The following analog sensors and circuits may be used in various applications: - Hydraulic Pressure Sensor - Coolant Temperature Sensor - Atmospheric Pressure Sensor - Turbocharger Inlet Pressure Sensor * - Turbocharger Outlet (Boost) Sensor - Lubrication Oil Pressure Sensor - Hydraulic Oil Temperature Sensor - Fuel Temperature Sensor * Not all applications
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HEUI SYSTEM
8 OR 12 INJECTORS
COMPONENT DIAGRAM ADEM II ELECTRONIC CONTROL MODULE (ECM)
ENGINE HARNESS
GROUND BOLT
DISCONNECT SWITCH
24 V
MACHINE HARNESS
HYDRAULIC PRESSURE SENSOR
TDC SERVICE PROBE ACCESS
MAIN 15 AMP POWER RELAY BREAKER
KEY SWITCH
MACHINE INTERFACE CONNECTOR
PRIMARY SPEED/TIMING SENSOR SECONDARY SPEED/TIMING SENSOR
104 • Hydraulic pressure sensor • Senses injector actuation pressure
The Hydraulic Pressure Sensor is located in the right side supply manifold and is used to measure injector actuation hydraulic pressure for the ECM. The ECM uses this pressure measurement to control the displacement of the Hydraulic Supply Pump (through the Pump Control Valve). The sensor has a range from 0 to 4.8 Volts output which corresponds to a pressure range of approximately 4000 to 33000 kPa (600 to 4800 psi). With the engine stopped, the default value when read with the service tool is 1800 kPa (260 psi).
• System defaults
The ECM will not activate the injectors to start the engine if the pressure is reading below 4500 kPa (650 psi). A fault will be generated if the actual hydraulic pressure differs from the desired system pressure by more than 1000 kPa (145 psi) for more than half a second. NOTE: Always use a wrench (not vise grip pliers) for removal and installation of all sensors.
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HEUI SYSTEM
8 OR 12 INJECTORS
COMPONENT DIAGRAM ADEM II ELECTRONIC CONTROL MODULE (ECM)
ENGINE HARNESS
GROUND BOLT
DISCONNECT SWITCH
24 V
MACHINE HARNESS
HYDRAULIC PRESSURE SENSOR
TDC SERVICE PROBE ACCESS
MAIN 15 AMP POWER RELAY BREAKER
KEY SWITCH
MACHINE INTERFACE CONNECTOR
PRIMARY SPEED/TIMING SENSOR SECONDARY SPEED/TIMING SENSOR
COOLANT TEMP. SENSOR
105 • Coolant temperature sensor
The Coolant Temperature Sensor supplies the temperature signal for the following functions: - Caterpillar Monitoring System or VIMS instrument display - Caterpillar Monitoring System or VIMS warning lamps and alarm - Demand Control Fan (if so equipped) - ET or ECAP coolant temperature display - High coolant temperature event logged above 107°C (225°F) - Engine Warning Derate when 107°C (225°F) is exceeded or low oil pressure occurs (if so equipped) - Back-up sensor to the hydraulic oil temperature sensor for ether aid operation NOTE: All analog sensors use the common analog power supply of 5.0 ± 0.2 Volts.
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HEUI SYSTEM
8 OR 12 INJECTORS
COMPONENT DIAGRAM ADEM II ELECTRONIC CONTROL MODULE (ECM)
ENGINE HARNESS
GROUND BOLT
DISCONNECT SWITCH
24 V
MACHINE HARNESS
HYDRAULIC PRESSURE SENSOR
MAIN 15 AMP POWER RELAY BREAKER
KEY SWITCH
MACHINE INTERFACE CONNECTOR
TDC SERVICE PROBE ACCESS
PRIMARY SPEED/TIMING SENSOR SECONDARY SPEED/TIMING SENSOR
COOLANT TEMP. SENSOR
ATMOSPHERIC PRESS. SENSOR
106 • Atmospheric pressure sensor • Used to calculate gauge pressure
• Two methods used to calibrate sensors
• Four main functions
All pressure sensors (except hydraulic actuation) in the system measure absolute pressure and, therefore, require the atmospheric sensor to calculate gauge pressure. The sensors are used both individually (absolute pressure) in the case of atmospheric pressure, and as a pair to calculate oil and boost pressures (gauge pressures). All the pressure sensor outputs are matched to the Atmospheric Pressure Sensor output during calibration. Calibration can be accomplished using the ET service tool or by turning on the key start switch without starting the engine for five seconds to automatically calibrate the sensors. The Atmospheric Pressure Sensor performs four main functions: 1. Automatic Altitude Compensation (maximum derate 24%) 2. Automatic Filter Compensation (maximum derate 20%) 3. Part of pressure calculation for gauge pressure readings 4. Reference sensor for pressure sensor calibration A foam filter is installed below the sensor to prevent the entry of dirt.
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ENGINE POWER DERATING MAP ACCORDING TO ATMOSPHERIC PRESSURE 7,500
98%
8,210
96%
8,920
94%
9,630
92%
10,340
ALTITUDE IN FEET
100%
11,050
90%
11,760
88%
12,470
86%
13,180
84%
13,890
82%
14,600
80% 78%
15,310
76%
16,020
74%
16,730
72%
17,440 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53
ATMOSPHERIC PRESSURE IN kPa
107 • Automatic altitude compensation
Atmospheric pressure measurement by the sensor provides an altitude reference for the purpose of Automatic Altitude Compensation. The graph shown here describes how derating on a typical 3408E/3412E starts at 7500 ft. and continues linearly to a maximum of 17000 ft. Other engines may start as low as 4000 ft. depending on the application.
• System continually adjusts to optimum power setting
The advantage of the HEUI system is that the engine always operates at the correct derating setting at all altitudes. The system continually adjusts to the optimum setting regardless of altitude, so the engine will not exhibit a lack of power or have smoke problems during climbs or descents to different altitudes. NOTE: The HEUI system has an advantage over a mechanical fuel system which is derated in "altitude blocks" (i.e. 7500 ft., 10000 ft., 12500 ft.). HEUI derating is continuous and automatic. Therefore, a machine operating in the lower half of the block is not penalized with low power. Conversely, a machine operating in the upper half of the block will not overfuel with the HEUI system.
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HEUI SYSTEM
8 OR 12 INJECTORS
COMPONENT DIAGRAM ADEM II ELECTRONIC CONTROL MODULE (ECM)
ENGINE HARNESS
GROUND BOLT
DISCONNECT SWITCH
24 V
MACHINE HARNESS
HYDRAULIC PRESSURE SENSOR
MAIN 15 AMP POWER RELAY BREAKER
KEY SWITCH
MACHINE INTERFACE CONNECTOR
TDC SERVICE PROBE ACCESS
PRIMARY SPEED/TIMING SENSOR SECONDARY SPEED/TIMING SENSOR
TURBO INLET PRESSURE SENSOR
COOLANT TEMP. SENSOR
ATMOSPHERIC PRESS. SENSOR
108 • Turbo inlet pressure sensor
The Turbocharger Inlet Pressure Sensor is used with the Atmospheric Pressure Sensor to measure air filter restriction.
• Sensors enable automatic air filter compensation
These two sensors are used to enable the Automatic Air Filter Compensation function (if so equipped.) This sensor is also used as a back-up to the Atmospheric Pressure Sensor for Automatic Altitude Compensation.
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AUTOMATIC AIR FILTER COMPENSATION TURBOCHARGER INLET PRESSURE SENSOR
ATMOSPHERIC PRESSURE SENSOR
CAT
Filter differential pressure calculated with formula: Atmospheric sensor pressure - Turbo sensor pressure = ∆P Fuel limited 2% per 4 inches H20 to max 20%
109 • Automatic filter compensation
Automatic Filter Compensation means that the engine is protected against the effects of plugged filters. Derating is automatic as follows: - Air filter restriction (∆P) exceeds 6.25 kPa (30 in. of water) *
• Derating starts above 30 in. ∆P
- Engine power derating starts at the rate of 2% per 1 kPa of ∆P - Maximum derate is 20% - Event is logged when air filter restriction (∆P) exceeds 6.25 kPa (30 in. of water) * * These specifications are typical examples. The actual values may vary depending on the application. Derating is retained at the maximum ∆P until the key start switch is cycled off and on. NOTE: If only one filter is plugged, the ET service tool and Caterpillar Monitoring System will display the highest ∆P of the two. Derating is also based on the highest ∆P of the two.
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HEUI SYSTEM
8 OR 12 INJECTORS
COMPONENT DIAGRAM ADEM II ELECTRONIC CONTROL MODULE (ECM)
ENGINE HARNESS
GROUND BOLT
DISCONNECT SWITCH
24 V
MACHINE HARNESS
HYDRAULIC PRESSURE SENSOR
TDC SERVICE PROBE ACCESS
MAIN 15 AMP POWER RELAY BREAKER
KEY SWITCH
MACHINE INTERFACE CONNECTOR
PRIMARY SPEED/TIMING SENSOR SECONDARY SPEED/TIMING SENSOR
TURBO INLET PRESSURE SENSOR
COOLANT TEMP. SENSOR
TURBO OUTLET PRESS. SENSOR
ATMOSPHERIC PRESS. SENSOR
110 • Turbo outlet pressure sensor
The Turbocharger Outlet Pressure Sensor measures absolute pressure downstream of the aftercooler. Boost (gauge) pressure can be read with the service tools. This measurement is a calculation using the Atmospheric Pressure and the Turbocharger Outlet Pressure Sensors. A failure of this sensor can cause the engine to derate as much as 60% when the ECM defaults to a zero boost condition.
• Air/fuel ratio control
The function of the sensor is to enable the Air/Fuel Ratio Control which reduces smoke, emissions and maintains engine response during acceleration. The system utilizes boost pressure, atmospheric pressure and engine speed to control the air/fuel ratio. Engine fuel delivery is limited according to a map of gauge turbo outlet (boost) pressure and engine speed. The Air/Fuel Ratio Control setting is not adjustable in machine applications. INSTRUCTOR NOTE: The pressure calculations and purposes of these calculations for all sensors are tabulated later in the presentation.
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HEUI SYSTEM
8 OR 12 INJECTORS
COMPONENT DIAGRAM ADEM II ELECTRONIC CONTROL MODULE (ECM)
ENGINE HARNESS
GROUND BOLT
DISCONNECT SWITCH
24 V
MACHINE HARNESS
HYDRAULIC PRESSURE SENSOR
MAIN 15 AMP POWER RELAY BREAKER
KEY SWITCH
MACHINE INTERFACE CONNECTOR
TDC SERVICE PROBE ACCESS
PRIMARY SPEED/TIMING SENSOR SECONDARY SPEED/TIMING SENSOR
TURBO INLET PRESSURE SENSOR
COOLANT TEMP. SENSOR
TURBO OUTLET PRESS. SENSOR
ATMOSPHERIC PRESS. SENSOR
OIL PRESSURE SENSOR
111 • Oil pressure sensor
Two pressure sensors are used for the measurement of oil (gauge) pressure: - Oil Pressure Sensor - Atmospheric Pressure Sensor PRESSURE CALCULATIONS
• Calculations are used to determine gauge pressure
MEASUREMENT Oil pressure
MEASURED BY
RESULT
[oil press (A) - atmospheric (A)] = oil pressure (GP)
These measurements are used to determine oil pressure for the ET service tool, Caterpillar Monitoring System and to alert the operator that an abnormal condition exists. The sensor operating range is 0 to 690 kPa (0 to 100 psi) (A). NOTE: (A)
= absolute pressure
(GP) = gauge pressure
➥
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PRESSURE CALCULATIONS
MEASUREMENT
MEASURED BY
RESULT
1. Atmospheric pressure
atmospheric sensor
= ambient press (absolute)
2. Air filter differential
Atmospheric - turbo inlet
= filter ∆ pressure
3.
turbo outlet - atmospheric
= boost (gauge press)
4. 5.
Boost Manifold press. absolute Oil pressure
turbo outlet sensor
= boost (absolute press)
oil press - atmospheric
= oil press (gauge press)
These measurements are used to determine: 1. Automatic Altitude Compensation 2. Automatic Air Filter Compensation (and Restriction Indication) 3. ET Boost Measurement 4. Caterpillar Monitoring System Oil Pressure Indication (Lubrication) 5. Altitude
NOTE: ∆ pressure = differential pressure
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49.3
320
46.4
300
43.5
280
40.6
OIL PRESSURE IN PSI
OIL PRESSURE IN kPa
OIL PRESSURE MAP 340
260 240 220 200 180 160 140 120
37.7 34.8 31.9 29 26.1 23.2 20.3 17.4
100
14.5
80
11.6
60 600
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
8.7 2000
ENGINE RPM kPa x 0.145 = PSI
112 • Oil pressure map
• Determines correct pressure for all rpm
Engine oil pressure varies with engine speed. As long as oil pressure increases above the upper line after the engine has been started and is running at low idle, the ECM reads adequate oil pressure. No faults are indicated and no logged event is generated. If the engine oil pressure decreases below the lower line, the following occurs: - An event is generated and logged in the permanent ECM memory. - A Category 3 Warning (alert indicator, action lamp and alarm) is generated on Caterpillar Monitoring System (if so equipped). - The engine is derated (if so equipped) to alert the operator. The two lines are sufficiently separated to prevent multiple alarms and events or a flickering lamp. This pressure separation is referred to as "hysteresis."
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HEUI SYSTEM
8 OR 12 INJECTORS
COMPONENT DIAGRAM ADEM II ELECTRONIC CONTROL MODULE (ECM)
ENGINE HARNESS
GROUND BOLT
DISCONNECT SWITCH
24 V
MACHINE HARNESS
HYDRAULIC PRESSURE SENSOR
MAIN 15 AMP POWER RELAY BREAKER
KEY SWITCH
MACHINE INTERFACE CONNECTOR
TDC SERVICE PROBE ACCESS
PRIMARY SPEED/TIMING SENSOR SECONDARY SPEED/TIMING SENSOR
TURBO INLET PRESSURE SENSOR
COOLANT TEMP. SENSOR
TURBO OUTLET (BOOST) PRESS. SENSOR ATMOSPHERIC PRESS. SENSOR
OIL PRESSURE SENSOR
HYDRAULIC TEMP. SENSOR
113 • Hydraulic oil temperature sensor • Enables automatic viscosity compensation
• Ether aid temperature reference
The Hydraulic (engine) Oil Temperature Sensor is used by the ECM to compensate for the effects of oil temperature on fuel injector timing and fuel delivery. This compensation provides consistent engine operation throughout a variety of operating conditions. Cold start protection with Cold Mode Timing is activated when the oil temperature decreases below a preset value of 60°C (140°F). The ether injection system uses this sensor as its temperature reference. NOTE: Without oil temperature monitoring, viscosity changes due to changes in oil temperature could cause unacceptable variations in engine performance (including exhaust emissions).
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HEUI SYSTEM
8 OR 12 INJECTORS
COMPONENT DIAGRAM ADEM II ELECTRONIC CONTROL MODULE (ECM)
ENGINE HARNESS
GROUND BOLT
DISCONNECT SWITCH
24 V
MACHINE HARNESS
HYDRAULIC PRESSURE SENSOR
TDC SERVICE PROBE ACCESS
MAIN 15 AMP POWER RELAY BREAKER
KEY SWITCH
MACHINE INTERFACE CONNECTOR
PRIMARY CAM SPEED/TIMING SENSOR BACKUP CAM SPEED/TIMING SENSOR
TURBO INLET PRESSURE SENSOR
COOLANT TEMP. SENSOR
TURBO OUTLET PRESS. SENSOR
ATMOSPHERIC PRESS. SENSOR
OIL PRESSURE SENSOR
HYDRAULIC TEMP SENSOR
FUEL TEMPERATURE SENSOR
114 • Fuel temperature sensor • Enables fuel temperature compensation
The ECM uses fuel temperature measurement to make corrections to the fuel rate to maintain power regardless of fuel temperature (within certain parameters). This feature is called "Fuel Temperature Compensation." The sensor output should be between 0.4 and 4.6 Volts.
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HEUI SYSTEM
8 OR 12 INJECTORS
COMPONENT DIAGRAM ADEM II ELECTRONIC CONTROL MODULE (ECM)
ENGINE HARNESS
GROUND BOLT
DISCONNECT SWITCH
24 V
MACHINE HARNESS
HYDRAULIC PRESSURE SENSOR
TDC SERVICE PROBE ACCESS
MAIN 15 AMP POWER RELAY BREAKER
KEY SWITCH
MACHINE INTERFACE CONNECTOR
PRIMARY SPEED/TIMING SENSOR SECONDARY SPEED/TIMING SENSOR
TURBO INLET PRESSURE SENSOR
COOLANT TEMP. SENSOR
TURBO OUTLET PRESS. SENSOR
ATMOSPHERIC PRESS. SENSOR
OIL PRESSURE SENSOR
HYDRAULIC TEMP. SENSOR
FUEL TEMPERATURE SENSOR
COOLANT FLOW SWITCH
115 • Coolant flow switch
The Coolant Flow Switch is installed in the oil cooler inlet. The switch connects the coolant flow terminal at the ECM P1/J1 connector to the digital return (ground) at the same connector. This ground is common with all digital sensors. The switch contacts are normally open with no flow. This circuit is used to provide the operator with a warning if a failure in the coolant circuit causing no flow occurs. The function may be checked using the status screen which will show if flow is present. This function should be checked both with the engine running and stopped.
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DIGITAL SENSORS AND CIRCUITS • Throttle Position • Pump Control Valve Signal • Exhaust Temperature
116 Digital Sensors and Circuits The following digital sensors and circuits may be used in the HEUI fuel system: - Throttle Position Sensor - Pump Control Valve Signal - Exhaust Temperature (not installed on machine engines at this time)
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HEUI SYSTEM
8 OR 12 INJECTORS
COMPONENT DIAGRAM ADEM II ELECTRONIC CONTROL MODULE (ECM)
ENGINE HARNESS
GROUND BOLT
DISCONNECT SWITCH
24 V
MACHINE HARNESS
HYDRAULIC PRESSURE SENSOR
TDC SERVICE PROBE ACCESS
PRIMARY SPEED/TIMING SENSOR
MAIN 15 AMP POWER RELAY BREAKER
KEY SWITCH
MACHINE INTERFACE CONNECTOR THROTTLE SENSOR
ACCELERATOR PEDAL
SECONDARY SPEED/TIMING SENSOR
TURBO INLET PRESSURE SENSOR
COOLANT TEMP. SENSOR
TURBO OUTLET PRESS. SENSOR
ATMOSPHERIC PRESS. SENSOR
OIL PRESSURE SENSOR
HYDRAULIC TEMP. SENSOR
FUEL TEMPERATURE SENSOR
COOLANT FLOW SWITCH
117 • Throttle position sensor
The Throttle Position Sensor provides engine speed control for the operator. At engine start-up, the engine rpm is set to low idle for two seconds to allow an increase of oil pressure before the engine is accelerated.
• 8-Volt digital sensor power supply
The Throttle Position Sensor receives 8 Volts from the Digital Sensor Power Supply at the ECM.
• Throttle functional check
A functional check of the throttle control system can be performed by connecting ET and monitoring the throttle position on the status screen as the throttle is moved slowly in both directions. The status screen will show between 0 and 100% of throttle position. (This reading should not be confused with the duty cycle percentage.) NOTE: This system eliminates all mechanical linkage between the operator's engine speed controls and the governor (ECM).
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PULSE WIDTH MODULATED SIGNALS 10% ON DUTY = 10% CYCLE OFF 50% ON DUTY = 50% CYCLE OFF 1 CYCLE 90% ON DUTY = 90% CYCLE OFF DUTY CYCLE = PERCENT OF TIME ON VS PERCENT OF TIME OFF
118 • Throttle position sensor signal
A Pulse Width Modulated (PWM) signal output is sent from the Throttle Position Sensor to the ECM. A PWM signal eliminates the possibility of an erroneous throttle signal due to a short causing a possible "run-away."
• Control defaults to low idle
If a signal problem occurs, the control defaults to a desired engine speed of low idle. If the ECM detects an out-of-normal range signal, the ECM ignores the Throttle Position Sensor signal and defaults to low idle. The sensor output is a constant frequency Pulse Width Modulated (PWM) signal to the ECM. For example, the Off-highway Truck sensor produces a duty cycle of 10 to 22% at the low idle position and 44 to 52% at the high idle position. The duty cycle can be read by the ECAP Service Tool and some digital multimeters. The percent of duty cycle is translated into a throttle position of 0 to 100% by the ECM, which can be read on the ET status screen. Other applications differ in PWM values for low and high idle. These values can be seen in the Troubleshooting Guide for the appropriate application.
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HEUI SYSTEM
8 OR 12 INJECTORS
COMPONENT DIAGRAM ADEM II ELECTRONIC CONTROL MODULE (ECM)
ENGINE HARNESS
GROUND BOLT
DISCONNECT SWITCH
24 V
MACHINE HARNESS
MAIN 15 AMP POWER RELAY BREAKER
KEY SWITCH
PUMP CONTROL VALVE
HYDRAULIC PRESSURE SENSOR
TDC SERVICE PROBE ACCESS
PRIMARY SPEED/TIMING SENSOR
MACHINE INTERFACE CONNECTOR THROTTLE SENSOR
ACCELERATOR PEDAL
SECONDARY SPEED/TIMING SENSOR
TURBO INLET PRESSURE SENSOR
COOLANT TEMP. SENSOR
TURBO OUTLET PRESS. SENSOR
ATMOSPHERIC PRESS. SENSOR
OIL PRESSURE SENSOR
HYDRAULIC TEMP. SENSOR
FUEL TEMPERATURE SENSOR
COOLANT FLOW SWITCH
119 • Pump control valve
The Pump Control Valve is used to control the swashplate angle in the hydraulic pump. By varying the PWM signal from the ECM to the solenoid, the valve controls the volume of hydraulic flow to case drain (as previously explained). PWM signals for the Pump Control Valve are used to maintain precise control of current values. The frequency of the power supply creates constant valve movement which helps the valve to maintain stable pressures. The Pump Control Valve may also be referred to as the "Injection Actuation Pressure Control Valve."
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HEUI SYSTEM
8 OR 12 INJECTORS
COMPONENT DIAGRAM ADEM II ELECTRONIC CONTROL MODULE (ECM)
ENGINE HARNESS
GROUND BOLT
DISCONNECT SWITCH
24 V
MACHINE HARNESS
MAIN 15 AMP POWER RELAY BREAKER
KEY SWITCH
PUMP CONTROL VALVE
HYDRAULIC PRESSURE SENSOR
MACHINE INTERFACE CONNECTOR
TDC SERVICE PROBE ACCESS
PRIMARY SPEED/TIMING SENSOR
THROTTLE SENSOR
SECONDARY SPEED/TIMING SENSOR
ACCELERATOR PEDAL THROTTLE BACK-UP, ELEVATED LOW IDLE ENABLE, AND GROUND LEVEL SHUTDOWN (2) SWITCHES TURBO INLET PRESSURE SENSOR
COOLANT TEMP. SENSOR
TURBO OUTLET PRESS. SENSOR
ATMOSPHERIC PRESS. SENSOR
OIL PRESSURE SENSOR
HYDRAULIC TEMP. SENSOR
FUEL TEMPERATURE SENSOR
COOLANT FLOW SWITCH
120 Engine Shutdown Systems • Ground level shutdown switch
The Ground Level Shutdown Switch is connected to the ECM through the machine and engine wiring harnesses. The switch signals the ECM to cut electrical power to the injectors, but maintains power to the ECM. This feature also enables the engine to be cranked without starting for maintenance purposes. No other circuits may be connected to this system. The user defined shutdown may be used in conjunction with other circuits. Not all machines will have this feature installed.
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USER DEFINED SHUTDOWN
USER SHUTDOWN DEVICE
J3
P2 J2
12
1
ECM (3408E/3412E HEUI) USER SHUTDOWN
121 • User defined shutdown input
The User Defined Shutdown feature (if installed) may be used to connect another device to the system to shut down the engine (such as a customer installed fire suppression system). When the shutdown input is grounded for one second, the engine will stop running. The input must be pulled down below 0.5 Volts before the ECM will recognize the shutdown signal. Operation of the User Defined Shutdown is logged as an event and can be shown on the ET status screen.
• Safety feature
When installed on an Off-highway Truck, this feature is programmed to function only during the following conditions for safety reasons: - Parking brake is ENGAGED - Transmission is in NEUTRAL - Machine ground speed is at zero Not all machines will have this feature installed.
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HEUI SYSTEM
8 OR 12 INJECTORS
COMPONENT DIAGRAM ADEM II ELECTRONIC CONTROL MODULE (ECM)
ENGINE HARNESS
GROUND BOLT
DISCONNECT SWITCH
24 V
MACHINE HARNESS
MAIN 15 AMP POWER RELAY BREAKER
KEY SWITCH
PUMP CONTROL VALVE
HYDRAULIC PRESSURE SENSOR
MACHINE INTERFACE CONNECTOR
TDC SERVICE PROBE ACCESS
PRIMARY SPEED/TIMING SENSOR
THROTTLE SENSOR
SECONDARY SPEED/TIMING SENSOR
ACCELERATOR PEDAL THROTTLE BACK-UP, ELEVATED LOW IDLE ENABLE, AND GROUND LEVEL SHUTDOWN (2) SWITCHES TURBO INLET PRESSURE SENSOR
COOLANT TEMP. SENSOR
FAN CONTROL VALVE TURBO OUTLET PRESS. SENSOR FAN SPEED SENSOR FAN ATMOSPHERIC PRESS. SENSOR
OIL PRESSURE SENSOR
HYDRAULIC TEMP. SENSOR
FUEL TEMPERATURE SENSOR
COOLANT FLOW SWITCH
122
Demand Fan Controls • Two thermostatic fan types: - Variable speed clutch - Hydraulic
Two types of thermostatic fans are used in 3408E/3412E machine applications. Some Off-highway Trucks, Track-type Tractors, Motor Graders and Paving Products are equipped with a variable speed fan drive clutch. Some Wheel Loaders are equipped with a hydraulic fan drive. Both systems use the ECM and the temperature sensor as the engine coolant temperature reference and both are controlled by the ECM. If an electrical failure of the systems occurs, the fans will go to maximum (100%) speed. The advantages of the systems are: 1. 2. 3. 4. 5.
Reduced fuel consumption in most conditions Reduced engine overcooling at low ambient temperatures Faster engine warm-up More engine power available at the flywheel Reduced noise
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ETHER INJECTION SYSTEM P2 J2
ETHER SWITCH
J3
P1 J1
P3
23 9 39 21
ECM (3408E/E3412E)
F708-YL 998-BR 721-GY 710-BR
28 29 19 40
ETHER SW LAMP DIGITAL RETURN ETHER REQUEST ETHER CONTROL
200-BK 200-BK +
308-YL
+24V
P37 J37 1 2
310-PK
RELAY
ETHER START VALVE
FROM CYLINDER
TO ENGINE
123 Ether Injection System The ECM controls the use of ether for cold starting. The ECM uses inputs from the speed/timing and hydraulic oil temperature sensors to determine the need for ether. The coolant temperature sensor is used as a back-up for the hydraulic oil temperature sensor. • Ether injection parameters
The ECM cycles the ether for three seconds on and three seconds off. Actual flow is determined by engine speed and temperature. Ether injection is disabled when the oil temperature exceeds 10°C (50°F) or engine speed exceeds 1200 rpm. A manual mode allows ether injection when the above parameters permit. In the manual mode, a precise quantity of ether is injected. The ether injection status can be read on the ET status screen.
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SERVICE TOOL CONNECTOR
CAT DATA LINK LAPTOP COMPUTER
CONTROL
SERVICE TOOL
CAT ELECTRONIC TECHNICIAN 7X1701 COMMUNICATION
VIMS
ADEM II ELECTRONIC CONTROL MODULE (ECM)
MAIN MODULE
ADAPTER
VIMS DISPLAY MODULES
124 CAT Data Link • CAT Data Link • Link between various systems
• Service tool connector
The CAT Data Link is the communication link between the ECM, EPTC II, Caterpillar Monitoring System, ET Service Tool, PC based software and other onboard/off board microprocessor based systems. The CAT Data Link allows the various onboard systems to communicate with each other through a two wire connection. Up to 10 systems can be connected on a machine. The CAT Data Link is used for programming and troubleshooting the electronic modules used with Caterpillar service tools through the Service Tool Connector. The ET service tool is connected through the Service Tool Connector. If a Personality Module is not installed in the ECM, the service tool will not be able to communicate with the ECM.
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988F/990 CAT DATA LINK CIRCUIT
POWERTRAIN CONTROL MODULE Cat Data Link + Cat Data Link -
SERVICE TOOL CONNECTOR
CMS 8 9
J42 D E H J
23 24
P3 J3 7 6 31 32
Cat Data Link + Cat Data Link -
893-GN 892-BR E794-YL E-793-BU
ECM P1 J1 9 Cat Data Link + 3 Cat Data Link 7 ATA Data Link + 1 ATA Data Link -
MACHINE INTERFACE CONNECTOR
125
• Data link wires twisted to reduce RFI
The CAT Data Link is a two wire (twisted pair) electrical connection used for communication between electronic modules that use the CAT Data Link. The cables are twisted to reduce radio frequency interference. Typical systems connected by the data link are: - ECM - Caterpillar Monitoring System Modules - Caterpillar ET or ECAP Service Tools - Transmission Control Module The ECM communicates with the Caterpillar Monitoring System, Vital Information Management System (VIMS) or Computer Monitoring System (CMS) to share engine information such as engine speed, engine oil pressure, coolant temperature, filter restriction, and electronic system faults.
• Two data link systems
Two Data link systems are used. The CAT Data Link circuit is used for normal diagnostic and programming functions and the ATA Data Link is used for flash programming.
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LOGGED EVENTS •
High coolant temperature
•
Loss of coolant flow
•
Low (lube) oil pressure
•
Abnormal hydraulic pressure
•
Hydraulic system pressure fault
•
User defined shutdown
•
Air inlet restriction
•
Engine overspeed
•
Low fuel pressure 126 Logged Events
• Logged events
Logged events as listed on the appropriate ET screen are conditions which are abnormal to the operation of the engine (for example: high temperature, low pressure or excessive engine speed). These conditions would not normally be caused by an electronic problem. Some of the parameters listed in this presentation are used in the ET events list. They are:
• Event list
- High coolant temperature above 107°C (225°F) - Loss of coolant flow - Low (lubrication) oil pressure (according to the oil pressure map) - Abnormal injection actuation hydraulic pressure (low or high) - Injection actuation pressure system fault - User defined shutdown (if installed) - Air inlet restriction (if installed) - Engine overspeed histogram - Low fuel pressure (industrial engine only)
➥
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All the parameters listed on the previous page can be read on the ET status screens (except for a hydraulic system fault). Events are not logged if an electronic fault is detected. • Passwords required to clear events
Passwords are required to clear events. This process would normally be performed during an engine overhaul. At other times, the events would be left as a record of the engine history prior to overhaul time.
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HEUI SYSTEM
8 OR 12 INJECTORS
COMPONENT DIAGRAM ADEM II ELECTRONIC CONTROL MODULE (ECM)
ENGINE HARNESS
GROUND BOLT
DISCONNECT SWITCH
24 V
MACHINE HARNESS
MAIN 15 AMP POWER RELAY BREAKER
KEY SWITCH
PUMP CONTROL VALVE HYDRAULIC PRESSURE SENSOR
MACHINE INTERFACE CONNECTOR
TDC SERVICE PROBE ACCESS
PRIMARY SPEED/TIMING SENSOR
THROTTLE SENSOR
ACCELERATOR PEDAL
SECONDARY SPEED/TIMING SENSOR
THROTTLE BACK-UP, ELEVATED LOW IDLE ENABLE, AND GROUND LEVEL SHUTDOWN (2) SWITCHES TURBO INLET PRESSURE SENSOR
COOLANT TEMP. SENSOR
FAN CONTROL VALVE TURBO OUTLET PRESS. SENSOR FAN SPEED SENSOR FAN ATMOSPHERIC PRESS. SENSOR CAT DATA LINK SERVICE TOOL CONNECTOR
OIL PRESSURE SENSOR
EPTC II TRANSMISSION CONTROL HYDRAULIC TEMP SENSOR
AUTO RETARDER CONTROL
FUEL TEMPERATURE SENSOR INSTRUMENT PANEL COOLANT FLOW SWITCH
127 INSTRUCTOR NOTE: To reinforce this presentation, review the various sensor and component functions shown above. The following tasks can be demonstrated: Opens and shorts in analog and digital sensors Status screens with pressure and temperature readings Check switch status for all system switches Opens and shorts in throttle sensor (check operation with ET) Override fan speed control Identify connectors, trace sensor circuits and perform continuity checks Check for active and logged faults Check events and overspeed histogram
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MACHINE APPLICATIONS
128 MACHINE APPLICATIONS This section of the presentation covers the specific systems and related circuits in the 3408E/3412E HEUI fuel system in the following applications: - D9R/D10R Track-type Tractors - 988F/990 Series II Wheel Loaders - 769D/771B/773B/775B Off-highway Trucks - 3408E/3412E Industrial Engines
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DECELERATION POSITION SENSOR CIRCUIT
F702-GN
DECELERATION POSITION SENSOR +V DIGITAL DIGITAL RETURN SIGNAL
P38 J38
A B C
P2 J2
ECM (3408E/3412E)
24
DECEL POSITION
P1 J1
A700-OR 998-BR
35 29
+V DIGITAL SUPPLY DIGITAL RETURN
129 D9R/D10R Track-type Tractors • Throttle deceleration sensor
The Throttle Deceleration Position Sensor works similarly to a throttle position sensor, but in reverse. The Track-type Tractor has a decelerator pedal which, when in the released position, is wide open (high idle) and, when fully depressed, is in the low idle position. This digital sensor is identical to a normal throttle position sensor, but is connected mechanically in reverse to function as described above. The sensor position (% throttle) can be read on the service tool status screen. The sensor functions in conjunction with the Throttle Switch.
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THROTTLE SWITCH CIRCUIT
ECM (3408E/3412E)
THROTTLE SWITCH P1 J1 F715-PU F718-BU F716-WH F717-YL 998-BR
2 20 8 14 29
THROTTLE - LOW IDLE THROTTLE - H.I. PARITY THROTTLE - L.I. PARITY THROTTLE - HIGH IDLE DIGITAL RETURN
130 • Throttle switch
The Throttle Switch is used in conjunction with the throttle deceleration position sensor to control engine speed. This momentary rocker switch replaces the throttle lever in the previous mechanical fuel system. When held in the forward position, the switch will cause the engine to go to high idle. If momentarily rocked to the rearward position, it will cause the engine to return to low idle.
• Speed setting function
If the switch is held in the forward position for two seconds with the decelerator holding the rpm at the desired level, the engine speed will be set at that rpm. Subsequently moving the switch in either direction will move the engine to low or high idle. The switch position can be read on the service tool status screen.
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CRANK WITHOUT INJECTION PLUG CIRCUIT
ECM (3408E/3412E) CRANK WITHOUT INJECTION PLUG PLUG "HHH" J24 P24 BK
3 2 1
P1 J1
720-GN 719-BR 998-BR
25 24 29
CRANK W/O INJECT (NO) CRANK W/O INJECT (NC) DIGITAL RETURN
PLUG "JJJ" BK
131 • Crank without injection plug
The Crank Without Injection Plug is used to disable the injectors for maintenance purposes. The plug "HHH" must be replaced by the plug "JJJ" to enable the Crank Without Injection feature. One of the two plugs must be installed at all times or a diagnostic message will be generated. The plugs are installed close to the ECM in the engine compartment.
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MECHANICAL ENGINE FAN CONTROL CIRCUIT ENGINE FAN SOLENOID VALVE P41 J41
B C
F700-BU E799-BR F703-GY
ENGINE FAN SPEED SENSOR +V DIGITAL DIGITAL RETURN SIGNAL
J84 P84
A B C
P2 J2
ECM (3408E/E3412E)
19 7 25
VARIABLE FAN CLUTCH PWM DR AND SOL RETURN ENGINE FAN SPEED
P1 J1
A700-OR 998-BR
35 29 13
+V DIGITAL SUPPLY DIGITAL RETURN A/C ON (INPUT FROM COMPRESSOR SWITCH)
132 • Variable speed fan drive clutch
The cooling fans for some Off-highway Trucks, the D10R Track-type Tractor and the 24H Motor Grader are driven by a fan belt through a variable speed clutch which is controlled by the ECM. A solenoid valve varies the oil pressure to the clutch to control the fan speed.
• Fan speed sensor
A digital speed sensor is used as a reference for fan speed and is mounted on the clutch. This sensor is powered from the digital power supply.
• Coolant temperature sensor
• AC fan control
The Coolant Temperature Sensor is used as a reference for fan control as engine temperature varies. The speed of the fan is a function of coolant temperature. Below 88°C (190°F), the fan rotates slowly. At 98°C (208°F), the fan speed is maximum. Between those temperatures, fan speed is modulated. The fan speed control can be overridden by the service tool for testing purposes. For safety reasons, the fan will rotate slowly when the engine is started cold. The engine fan will turn at minimum speed when the air conditioning compressor switch closes and sends a signal to the ECM.
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THROTTLE LOCK CIRCUIT RIGHT BRAKE PEDAL SWITCH
P1 J1
998-BR
F722-OR F721-GY 998-BR F706-PU F717-YL F718-BU F719-BR
998-BR J3 P3
THROTTLE LOCK LAMP
2 113-OR BATT+
13 19 29 27 14 20 24
ECM Throttle Lock RH Brake (NO) Throttle Lock RH Brake (NC) Digital Return Throttle Lock ON Lamp Throttle Lock Set/Declerate Throttle Lock Resume/Accelerate Throttle Lock ON/OFF
998-BR THROTTLE LOCK SET/DECLERATION SW 998-BR THROTTLE LOCK RESUME/ACCLERATION SW 998-BR THROTTLE LOCK SW
133 988F/990 Series II Wheel Loaders • Throttle lock enable switch
• Throttle lock lamp
The Throttle Lock permits the operator to maintain engine speed without having to hold the throttle down for long periods. A rocker switch enables the feature. The Throttle Lock Lamp indicates the status of the Throttle Lock. The lamp ON indicates the feature is active. NOTE: The Throttle Lock System functions similarly to an automotive speed control system, except that it controls engine speed while cruise control functions with ground speed.
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• Set/deceleration switch
After the engine speed has been set by the throttle lock, the engine speed can be reduced 20 rpm by momentarily pressing the Set/Deceleration Switch. The engine speed can be lowered incrementally by 50 rpm per second while holding the switch down.
• Resume/acceleration switch
The Resume/Acceleration Switch can be used to increase speed by 20 rpm by momentarily pressing the Resume/Acceleration Switch. The engine speed can be raised incrementally by 50 rpm per second while holding the switch down.
• Right brake pedal switch
Depressing the Right Brake Pedal Switch will disable the throttle lock. An invalid brake switch signal will also disable the throttle lock feature.
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HYDRAULIC ENGINE FAN CONTROL CIRCUIT
HYDRAULIC FAN SOLENOID VALVE P2 J2
P86 J86 2 1
F700-BU E799-BR
19 07
ECM (3408E/E3412E) HYDRAULIC FAN PWM DRIVE AND SOL RETURN
134 • Fan driven by hydraulic motor
The 990 Series II Wheel Loader has an optional high ambient cooling fan which is driven by a hydraulic motor and controlled by the ECM.
• Hydraulic fan solenoid valve
The Hydraulic Fan Solenoid Valve controls the supply of oil to the hydraulic motor to increase or decrease fan speed. The Coolant Temperature Sensor is used as a reference for fan control as engine temperature varies. Above 98°C (208°F), the fan speed is maximum. As the temperature decreases below 95°C (203°F), the fan speed is minimum. Fan speed will also change as hydraulic pump output varies with engine speed. The fan speed control can be overridden by the service tool for testing purposes. The fan speed will go to maximum if power to the control valve fails.
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CATERPILLAR MONITORING SYSTEM
P
15 10 5
25 X100
R 24 V
AUT
20
0
MPH km/h
44
30
135 769C/771C/773B/775B Off-highway Trucks • Caterpillar Monitoring System
The Caterpillar Monitoring System is an electronic monitoring system used on some HEUI powered machines including Off-highway Trucks. It has a similar look to the VIMS and includes the following: - Message Center Module - Speedometer/Tachometer Module - Four Gauge Cluster Module - Action Lamp and Action Alarm This system receives information over the CAT Data Link. The display components show the operator the condition of machine systems and system diagnostic information. This system replaces the Electronic Monitoring System (EMS) on earlier trucks.
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136 An ECM controlled pre-lubrication system is installed on the 3400 HEUI engines in Off-highway Trucks. • Caterpillar Pre-Lubrication System
The pre-lubrication pump and motor are activated by the key start switch. The system uses existing sensors to determine the need for pre-lubrication. After oil pressure is determined, the Electronic Programmable Transmission Control (EPTC II) signals the starter motor to begin cranking. The purpose of the pre-lubrication system is to prime the lubrication system with oil prior to cranking the engine, fill the filters if they have been changed and, ultimately, to minimize wear on the engine bearings during cold starts.
• Prelube components:
This view shows the following components:
1. Prelube relay
- Prelube relay (1)
2. Prelube motor
- Prelube motor (2)
3. Prelube pump
- Prelube pump (3)
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This Caterpillar designed system should not be confused with other prelubrication systems. The Caterpillar Pre-Lubrication System is integrated into the machine electronic system utilizing existing hardware. To enable the Caterpillar Pre-Lubrication System, the system must be turned on using the electronic service tool. After the system has been enabled, any time the operator turns the key start switch to the start position, the sequence will be as follows: 1. The EPTC II will not normally engage the starter relays until the engine ECM senses 48 kPa (7 psi) from the oil pressure sensor. This information is transmitted over the CAT Data Link. If the CAT Data Link is inoperative, the EPTC II will signal the engine to start. 2. The engine will bypass the pre-lubrication cycle during any of the following conditions: - If the engine has been running within two minutes - Coolant temperature is higher than 70°C (158°F) - Engine oil temperature is higher than 54°C (129°F) - Torque converter temperature is higher than 65°C (149°F) 3. If the engine or torque convertor is cold, the engine ECM will turn on the signal relay in the cab. This relay signals the prelubrication relay on the chassis to initiate the sequence. 4. The chassis mounted pump draws oil from the oil pan and directs it to the oil gallery. When 48 kPa (7 psi) oil pressure (using the oil pressure signal from the oil pressure sensor) is reached or 60 seconds has elapsed, the EPTC II will terminate pre-lubrication and engage the starter. 5. If the system "times out" after 60 seconds, a pre-lubrication system fault will be recorded in the ECM. After the system has timed out, the engine should start regardless of oil pressure. A pre-lubrication fault should not cause a failure to start the engine.
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8 OR 12 INJECTORS
ADEM II ELECTRONIC CONTROL MODULE (ECM)
INDUSTRIAL 3408E/3412E HEUI SYSTEM COMPONENT DIAGRAM GROUND BOLT
DISCONNECT SWITCH
15 AMP BREAKER
MAIN POWER RELAY
24 V KEY SWITCH
PUMP CONTROL VALVE HYDRAULIC PRESSURE SENSOR PRIMARY SPEED/TIMING SENSOR
MACHINE INTERFACE CONNECTOR
TDC SERVICE PROBE ACCESS
PTO ENABLE/PTO UP/DOWN SWITCHES ENGINE SHUTDOWN SWITCH ETHER ENABLE/OVERRIDE SWITCH EMERGENCY STOP/VERIFY SWITCH USER DEFINED SHUTDOWN
ENGINE HARNESS
SECONDARY SPEED/TIMING SENSOR
THROTTLE POSITION SENSOR
COOLANT TEMP. SENSOR
TURBO OUTLET PRESS. SENSOR
FUEL PRESS. SENSOR COOLANT LEVEL SWITCH
MACHINE HARNESS
INLET AIR TEMP. SENSOR ATMOSPHERIC PRESS. SENSOR TO AIR SHUTOFF SOLENOID OIL PRESSURE SENSOR
TO ETHER SOLENOID RELAY ALARM /WARNING LAMP
HYDRAULIC TEMP. SENSOR
DIAGNOSTIC LAMP FUEL TEMPERATURE SENSOR MAINTENANCE INDICATOR LAMP EMS PANEL SERVICE TOOL CONNECTOR DATA LINK
137 3408E/3412E HEUI Industrial Engines Although these industrial engines are very similar to the machine engines, some electronic differences exist between the machine and the industrial engines. The industrial engine has some component and software differences. Some components have been deleted and replaced by others. For example, the coolant flow switch is deleted and a coolant level switch may be installed as an option. A sophisticated Engine Warning System can be programmed to provide different levels of warning, derating and shutdown. These customer programmable parameters can be tailored to the customer's requirements. A complete description of these parameters is provided in the appropriate Troubleshooting Guide.
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The component differences are: Switches PTO Enable and Up/Down Switch Idle/Rated Speed Switch Emergency Stop Verify Switch (for Air Shutoff Solenoid) Engine Shutdown Switch
Sensors and Switches Inlet Air Temperature Sensor (optional) Coolant Level Sensor (optional, replaces the Coolant Flow Switch) Fuel Pressure Sensor (optional)
Miscellaneous Components Air Shutoff Solenoid Alarm and Diagnostic and Maintenance Indicator Lamps Caterpillar Engine Monitoring System
Software features Engine Warning Derate and Shutdown for: High coolant temperature Low oil pressure Low coolant level PTO operation Programmable Low Idle, Top Engine Limit and High Idle Maintenance Indicator Programmable Ether Aid Engine Speed and Load Histogram Multiple Engine Ratings with a Personality Module Ramp Speed (engine acceleration rate in PTO mode) Power Trim
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3408E/3412E HEUI FUEL SYSTEM TO LUBE SYSTEM
HEUI HYDRAULIC OIL TEMPERATURE SENSOR COLD START OIL RESERVOIR
OIL FILTER
COOL DOWN CIRCUIT
HYDRAULIC SUPPLY PUMP GROUP
OIL COOLER
FLUID MANIFOLD
OIL PRESSURE SENSOR
HYDRAULIC PRESSURE SENSOR
FUEL TEMPERATURE SENSOR
FLUID MANIFOLD
PUMP CONTROL VALVE
HEUI
ECM
FUEL TRANSFER PUMP
LUBE OIL PUMP
SECONDARY FUEL FILTER
PRIMARY FUEL FILTER WATER SEPARATOR
OIL SUMP
PRESSURE REGULATING VALVE
FUEL TANK
138 CONCLUSION The 3400 HEUI Engine control is a sophisticated system. However, like many modern electronic controls, it is user friendly and simpler to service than previous pump and line systems. The key to this simplicity is excellence in training. INSTRUCTOR NOTE: The circuits described in this presentation on the various HEUI applications can be demonstrated with the service tool. The following tasks can be performed: Opens and shorts in circuits Status screens to show speed control sensor and switch positions Override fan controls Pre-lubrication functional test Program industrial engine parameters
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SLIDE LIST 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44.
Title slide 3408 engine overview HEUI fuel system HEUI system major components 3408E engine top view 3408E engine upper left side view Timing calibration connector and hydraulic pressure sensor Coolant temperature sensor Secondary speed/timing sensor Timing wheel Turbo inlet sensor Turbo outlet sensor Identify components Lubrication oil pressure sensor Lubrication oil pump Timing calibration sensor Water separator Engine component identification Electronic control system ECM Personality module Injector Injector testing methods Timing control logic Electronic governor Component diagram Speed/timing sensors Timing wheel Speed/timing wheel Cranking After pattern recognition Normal operation Timing calibration sensor Timing calibration Injection current waveform Poppet valve movement Waveform and response characteristics Fuel system limits Fuel system cold modes Fuel system derates Fuel injection system HEUI fuel system System components Hydraulic supply pump group
45. 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. 66. 67. 68. 69. 70. 71. 72. 73. 74. 75. 76. 77. 78. 79. 80. 81. 82. 83. 84. 85. 86. 87. 88. 89.
HEUI fuel system--low pressure HEUI fuel system--high pressure HEUI fuel system--low pressure Injector--fuel and oil flow Injector fuel supply Fluid supply manifold (iron shot) Fluid supply manifold (sectional view) Jumper tube Injector current waveform Waveform and response Injector components HEUI unit injector--three main groups HEUI injector component parts Unit injector components Unit injector installation Valve body group Barrel group--fuel pressure Nozzle group Valve body group--solenoid de-energized Unit injector--end of injection Barrel group--refill Nozzle group--fuel edge filter Injection rate shaping graph Barrel prime rate shaping Barrel group--internal leaks Injector check valves Hydraulic injection pressure control Hydraulic supply pump group Hydraulic supply pump mounting adapter Hydraulic supply pump priming Fuel transfer pump Pressure regulating valve Cool down bypass circuit Reverse flow check valves (iron shot) Reverse flow check valve (sectional view) Hydraulic supply pump (cutaway front view) Hydraulic supply pump (cutaway side view) Fuel system--hydraulic system operation HEUI hydraulic control system--start-up Compensator assembly--start-up HEUI hydraulic control system--destroke Compensator valve--destroke HEUI hydraulic control system--upstroke Compensator valve--upstroke HEUI hydraulic control system--limiter
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SLIDE LIST 90. Compensator assembly--pressure limiter operation 91. Pump control valve--no current flow 92. Pump control valve--high current flow 93. HEUI system power supplies 94. Components diagram--power supply 95. ECM power supply circuit 96. Speed/timing sensor power supply 97. Injector wiring schematic 98. Analog sensor power supply 99. Digital sensor power supply 100. Pump control valve--power supply 101. Electronic sensors and systems 102. Speed/timing sensor 103. Analog sensor list 104. Hydraulic pressure sensor 105. Coolant temperature sensor 106. Atmospheric pressure sensor 107. Engine power derating map 108. Turbocharger inlet pressure sensor 109. Automatic filter compensation 110. Turbocharger outlet sensor 111. Oil pressure sensor 112. Oil pressure map 113. Hydraulic temperature sensor
114. Fuel temperature sensor 115. Coolant flow switch 116. Digital sensor list 117. Throttle position sensor 118. Pulse Width Modulated (PWM) signal 119. Pump control valve 120. Ground level shutdown switch 121. User defined shutdown input 122. Demand fan controls 123. Ether injection system 124. Cat Data Link diagram 125. Cat Data Link circuit 126. Logged events 127. System diagram 128. Machine applications 129. Deceleration position sensor circuit 130. Throttle switch circuit 131. Crank without injection plug circuit 132. Engine fan control circuit 133. Throttle lock circuit 134. Hydraulic engine fan control 135. 769C - 775B Dash 136. Pre-lubrication system 137. Industrial engine component diagram 138. HEUI fuel diagram
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Serviceman's Handout No. 1
HEUI Ref : 1672-01
-
Material_de_Estudiante
MODOS EN FRIO HEUI MODO EN_FRIO
Control de Velocidad Baja en vacio_elevado
PROPOSITO
PUNTOS DE_CAMBIO DE TEMPERATURA
Calentamiento rapido Engine protection
Limitacion de Combustible Cranking limit Improves starting by limiting fuel Prevents overfuelling during start-up
SENSOR
< 60°C
Temp. aceite
< 60°C
Temp. aceite
30°C to 90°C
Fuel temp.
Sincronizacion de Inyeccion Oil Viscosity Compensates for variations due to Compensation viscosity changes with oil temperature
< 60°C
Oil temp.
Cold Mode Timing
Optimum timing for cold running also reduces white smoke
< 60°C
Oil temp.
Presion de Inyeccion Cold mode cranking hydraulic pressure
Optimum hydraulic pressure for cold starting
< 60°C
Oil/Coolant temp.
Cold mode running hydraulic pressure
Optimum hydraulic pressure for cold running
< 60°C
Oil temp.
Oil Viscosity Compensation
Compensates for variations due to viscosity changes with oil temperature
All temperatures Oil temp.
Ether Injection Ether injection
Starting aid
< 10°C
Fuel Temperature Compensation
Provides advertised power between these between these values regardless of fuel temperature changes
Oil temp.
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Serviceman's Handout No. 3
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Serviceman's Handout No. 4
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Serviceman's Handout No. 5
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Serviceman's Handout No. 6
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Serviceman's Handout No. 7
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Serviceman's Handout No. 8
How small is a Micron? Human Hair 88 Micron .0035 Inch .0889 mm Magnified 2,000 times
1 Micron .00004 Inch .001 mm 2.5 Micron .0001 Inch .0025 mm 25 Micron .001 Inch .025 mm
5 Micron .0002 Inch .005 mm
25,400 Microns = 1 Inch
SESV1672-01 4/97
Printed in U.S.A.
