The engine is designed for electronic control. The engine has an Electronic Control Module (ECM), a fuel injection pump and electronic unit injectors. All of these items are electronically controlled. There are also a number of engine sensors. The engine is equipped with an electronically controlled wastegate for the turbocharger. The ECM controls the engine operating parameters through the software within the ECM and the inputs from the various sensors. The software contains parameters that control the engine operation. The parameters include all of the operating maps and customer-selected parameters.
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| Illustration 1 | g03734778 |
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A typical example of a block diagram for the engine (1) Valve for the NOx Reduction System (NRS) (2) Air cleaner (3) Air inlet temperature sensor (4) Exhaust Cooler for the NOx Reduction System (NRS) (5) Turbocharger (6) Engine intake throttle valve (7) Wastegate regulator (8) Air-to-air aftercooler (9) Engine exhaust gas pressure sensor (10) Engine exhaust gas temperature sensor (11) Crankshaft speed/timing sensor (12) Camshaft speed/timing sensor (13) Electronic unit injectors (14) Fuel injection pump (15) Fuel pressure sensor (16) Oil pressure switch (17) Coolant temperature sensor (18) Engine (19) Fuel transfer pump (20) Primary fuel filter with water-in-fuel sensor (21) Intake manifold air temperature/pressure sensor (22) Secondary fuel filter with fuel temperature sensor (23) Fuel tank | |
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| Illustration 2 | g03734787 |
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A typical example of a block diagram for the aftertreatment (24) Diesel Exhaust Fluid (DEF) temperature sensor (25) DEF level sensor (26) DEF quality sensor (27) Coolant diverter valve (28) DEF tank header unit (29) DEF tank (30) DEF pump pressure sensor (31) DEF pump filter (32) DEF pump module (33) DEF injector (34) Engine out NOx sensor (35) Diesel Oxidation Catalyst (DOC) inlet temperature sensor (36) DOC (37) DEF mixer (38) Selective Catalytic Reduction (SCR) inlet temperature sensor (39) SCR catalyst (40) Ammonia Oxidizing (AMOX) catalyst (41) SCR outlet temperature sensor (42) Tailpipe out NOx sensor (43) Ammonia sensor | |
Note: The ECM is not mounted on the engine.
The electronic control system has the following components:
- ECM
- Pressure sensors
- Temperature sensors
- Crankshaft speed/timing sensor
- Camshaft speed/timing sensor
- The suction control valve for the fuel injection pump
- Wastegate solenoid
- Electronic unit injectors
Sensor Locations for the Engine
The illustrations in this section show the typical locations of the sensors for the industrial engine. Specific engines may appear different from the illustration due to differences in applications.
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| Illustration 3 | g03734793 |
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Sensors and electrical connector locations on the left side of the engine (1) Inlet metering valve for the fuel injection pump (2) 10-pin engine interface connector (3) 62-pin engine interface connector (4) Fuel temperature sensor (5) Fuel pressure sensor (6) Oil pressure switch (7) Crankshaft speed/timing sensor (8) Water In Fuel (WIF) sensor | |
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| Illustration 4 | g03734799 |
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Close up view of sensors and electrical connector locations on the left side of the engine (1) Inlet metering valve for the fuel injection pump (2) 10-pin engine interface connector (3) 62-pin engine interface connector (4) Fuel temperature sensor (5) Fuel pressure sensor (6) Oil pressure switch (7) Crankshaft speed/timing sensor (8) Water In Fuel (WIF) sensor | |
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| Illustration 5 | g03734801 |
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Sensors and electrical connector locations on the right side of the engine (9) Exhaust gas valve for the NOx Reduction System (NRS) (10) Intake manifold air pressure and temperature sensor (11) Exhaust temperature sensor connector (12) Exhaust gas pressure sensor (13) Intake throttle valve (14) Coolant temperature sensor (15) Wastegate regulator (16) Secondary speed/timing sensor | |
Sensor Locations for the Clean Emissions Module
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| Illustration 6 | g03734805 |
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Typical view of the sensor locations on the CEM (17) Engine out NOx sensor (18) Diesel Exhaust Fluid (DEF) injector (19) Diesel Oxidation Catalyst (DOC)/DEF mixing chamber module (20) DOC inlet temperature sensor | |
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| Illustration 7 | g02722357 |
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Typical example | |
The Electronic Control Module (ECM) (1) functions as a governor and a computer for the fuel system. The ECM receives signals from the sensors in order to control the timing and the engine speed.
The electronic system consists of the ECM, the engine sensors, and inputs from the parent machine. The ECM is the computer. The personality module is the software for the computer. The personality module contains the operating maps. The operating maps define the following characteristics of the engine:
- Engine rating
- Torque curves
- High and low idle speed (rpm)
- Emissions
- Injection timing
Passwords restrict changes to authorized personnel. Refer to Troubleshooting for more information on the passwords.
The ECM has an excellent record of reliability. Any problems in the system are most likely to be the connectors and the wiring harness. The ECM should be the last item in troubleshooting the engine.
The programmable software contains all the fuel setting information. The information determines the engine performance.
Flash programming is the method of programming or updating the programmable software. Refer to Troubleshooting, "Flash Programming" for the instructions on the flash programming of the programmable software.
The ECM is sealed and the ECM needs no routine adjustment or maintenance.
The electronic controls determine the injection timing, the amount of fuel that is delivered to the cylinders and the intake manifold pressure if an electronically controlled wastegate is installed. These decisions are based on the actual conditions and the desired conditions at any given time.
The ECM has software that compares the desired engine speed to the actual engine speed. The actual engine speed is determined through the crankshaft speed/timing sensor and the camshaft speed/timing sensor. If the desired engine speed is greater than the actual engine speed, the ECM will instruct the electronic unit injector to inject more fuel in order to increase engine speed.
Once the ECM has determined the amount of fuel that is required, the software must determine the timing of the fuel injection. Fuel injection timing is determined by the ECM after considering input from the following components:
- Engine coolant temperature sensor
- The sensor for the intake manifold air temperature
- The sensor for the intake manifold pressure
At start-up, the ECM determines the top center position of the number 1 cylinder from the secondary speed/timing sensor on the camshaft. The ECM decides when fuel injection should occur relative to the top center position. The ECM optimizes engine performance by control of each of the electronic unit injectors so that the required amount of fuel is injected at the precise point of the engine's cycle. The electronic unit injectors are supplied high-pressure fuel from the fuel manifold. The ECM also provides the signal to the solenoid in the fuel injection pump. The solenoid in the fuel injection pump controls a valve in the fuel injection pump. This valve controls the volume of fuel that enters the plungers. By controlling the volume of fuel that enters the plungers, this controls the pressure in the fuel manifold. Fuel that is not required for the engine is diverted away from the fuel injection pump back to the fuel tank.
The ECM adjusts injection timing and fuel pressure for the best engine performance, the best fuel economy, and the best control of exhaust emissions. The actual timing can be viewed with an electronic service tool. Also, the desired timing can be viewed with an electronic service tool.
The programmable software inside the ECM sets certain limits on the amount of fuel that can be injected.
The FRC Limit is a limit that is based on intake manifold air pressure and engine rpm. The FRC Limit is used to control the air/fuel ratio in order to control the engines exhaust emissions. When the ECM senses a higher intake manifold air pressure, the ECM increases the FRC Limit. A higher intake manifold air pressure indicates that there is more air in the cylinder. When the ECM increases the FRC Limit, the ECM allows more fuel into the cylinder.
The Rated Fuel Limit is a limit that is based on the power rating of the engine and on the engine rpm. The Rated Fuel Limit enables the engine power and torque outputs to conform to the power and torque curves of a specific engine model.
These limits are in the programmable software and these limits cannot be changed.
The ECM controls the following characteristics:
- Boost pressure
- Operation of the NOx reduction system
When the ECM detects an electronic system problem, the ECM generates a diagnostic code. Also, the ECM logs the diagnostic code in order to indicate the time of the problems occurrence. The ECM also logs the number of occurrences of the problem. Diagnostic codes are provided in order to indicate that the ECM has detected an electrical problem or an electronic problem with the engine control system. In some cases, the engine performance can be affected when the condition that is causing the code exists.
If the operator indicates that a performance problem occurs, the diagnostic code may indicate the cause of the problem. Use a laptop computer to access the diagnostic codes. The problem should then be corrected.
Event Codes are used to indicate that the ECM has detected an abnormal engine operating condition. The ECM will log the occurrence of the event code. This does not indicate an electrical malfunction or an electronic malfunction. If the temperature of the coolant in the engine is higher than the permitted limit, then the ECM will detect the condition. The ECM will then log an event code for the condition.
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| Illustration 8 | g02722354 |
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Typical example | |
The crankshaft speed/timing sensor generates a signal by detecting the movement of the teeth that are located on the crankshaft timing ring (1). The signal that is generated by the speed/timing sensor is transmitted to the ECM. The ECM uses the signal from the speed/timing sensor to calculate the position of the crankshaft. The signal is also used to determine the engine speed.
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| Illustration 9 | g03699018 |
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Typical example | |
The camshaft speed/timing sensor generates a signal that is related to the camshaft position. The camshaft speed/timing sensor detects the movement of the position wheel on the front of the camshaft (2). The signal that is generated by the speed/timing sensor is transmitted to the ECM. The ECM calculates the speed and the rotational position of the engine by using the signal.
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| Illustration 10 | g03735136 |
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Schematic for speed/timing sensor | |
When the engine is cranking, the ECM uses the signal from the speed/timing sensor on the camshaft. When the engine is running the ECM uses the signal from the speed/timing sensor on the crankshaft. This speed/timing sensor is the primary source of the engine position.
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| Illustration 11 | g03735137 |
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Schematic for the pressure sensors on the ECM J2 connector | |
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| Illustration 12 | g03735138 |
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Schematic for the pressure sensors on the ECM J1 connector | |
The boost pressure sensor is an active sensor.
The boost pressure sensor provides the ECM with a measurement of inlet manifold pressure in order to control the air/fuel ratio. This will reduce the engine smoke during transient conditions.
An engine oil pressure switch is installed to the engine. While the engine is running and oil pressure is detected, the switch will be open. When no oil pressure is detected, the switch will be closed.
The ECM can warn the operator of possible conditions that can damage the engine. This includes the detection of an oil filter that is blocked.
The operating range for the engine oil pressure switch ...
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| Illustration 13 | g03735142 |
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Schematic for the temperature sensors on the ECM J2 connector | |
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| Illustration 14 | g03735143 |
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Schematic for the temperature sensors on the ECM J1 connector | |
The air inlet temperature sensor and the coolant temperature sensor are passive sensors. Each sensor provides a temperature input to the ECM. The ECM controls following operations:
- Fuel delivery
- Injection timing
The sensors are also used for engine monitoring.