The electronic control system has the following components:
- ECM
- Pressure sensors
- Temperature sensors
- Speed/timing sensors
- Intake throttle valve for the NOx Reduction System (NRS)
Illustration 1 is a block diagram of the control system
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| Illustration 1 | g06102915 |
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Typical example (1) Air cleaner (2) Diesel Oxidation Catalyst (DOC) (3) DOC inlet temperature sensor (if equipped) (4) DOC exhaust temperature sensor (if equipped) (5) Turbocharger (6) Intake throttle valve for the NOx Reduction System (NRS) (if equipped) (7) Valve for the NOx Reduction System (NRS) (8) Exhaust gas cooler (NRS) (9) Boost pressure sensor (10) Coolant temperature sensor (11) Primary speed/timing sensor (12) Secondary speed/timing sensor (13) Electronic Control Module (ECM) (14) Engine (15) Inlet manifold temperature sensor (16) Oil pressure switch (17) Engine glow plugs (18) Fuel temperature sensor (19) Secondary fuel filter (20) Fuel transfer pump (21) Primary fuel filter (22) Fuel tank | |
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.
Note: In the following illustrations, some components have been removed to improve visibility.
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| Illustration 2 | g03798752 |
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Typical sensor locations on the left side of the engine (1) Secondary speed/timing sensor (2) Coolant temperature sensor (3) Electronic unit injector (4) Exhaust gas valve for the NOx Reduction System (NRS) (5) Intake throttle valve for the NOx Reduction System (NRS) | |
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| Illustration 3 | g03798805 |
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Close-up views of typical sensor locations on the left side of the engine (1) Secondary speed/timing sensor (2) Coolant temperature sensor (3) Electronic unit injector (4) Exhaust gas valve for the NOx Reduction System (NRS) (5) Intake throttle valve for the NOx Reduction System (NRS) | |
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| Illustration 4 | g06090664 |
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Typical sensor locations on the right side and top of the engine (6) Boost pressure sensor (7) Air inlet temperature sensor (8) Oil pressure switch (9) Fuel pressure sensor (10) Fuel temperature sensor (11) Suction control valve for the fuel injection pump (12) Primary speed/timing sensor | |
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| Illustration 5 | g06090668 |
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Close-up views of typical sensor locations on the right side and top of the engine (6) Boost pressure sensor (7) Air inlet temperature sensor (8) Oil pressure switch (9) Fuel pressure sensor (10) Fuel temperature sensor (11) Suction control valve for the fuel injection pump (12) Primary speed/timing sensor | |
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| Illustration 6 | g06090608 |
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Typical sensor locations on the left side of the engine (1) Secondary speed/timing sensor (2) Coolant temperature sensor (3) Exhaust gas valve for the NOx Reduction System (NRS) (4) Electronic unit injector | |
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| Illustration 7 | g06090638 |
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Typical sensor locations on the right side and top of the engine (5) Air inlet temperature sensor (6) Boost pressure sensor (7) Oil pressure switch (8) Fuel pressure sensor (9) Fuel temperature sensor (10) Suction control valve for the fuel injection pump (11) Primary speed/timing sensor | |
Sensor Locations for the Clean Emissions Module
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| Illustration 8 | g03797799 |
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Sensors and components on a typical Clean Emissions Module (CEM) (1) DOC exhaust temperature sensor (if equipped) (2) DOC inlet temperature sensor (if equipped) | |
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| Illustration 9 | g03797803 |
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Typical example | |
The Electronic Control Module (ECM) (1) functions as a computer for the fuel system.
The electronic system consists of the ECM, the engine sensors, and inputs from the application. The ECM is the computer. The flash file is the software for the computer. The flash file 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
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 ECM has software that compares the desired engine speed to the actual engine speed. The actual engine speed is determined through the crankshaft speed sensor. If the desired engine speed is greater than the actual engine speed, the ECM will instruct the fuel injection pump to supply more fuel to the fuel injectors to increase engine speed.
The programmable software inside the ECM sets certain limits on the amount of fuel that can be provided to the fuel injectors.
The ECM controls the following characteristics:
- Fuel pressure
- Start of injection
- Injection duration
When the ECM detects an electronic system problem, the ECM generates a diagnostic code. Diagnostic codes are provided to indicate that the ECM has detected an electrical problem or an electronic problem with the engine control system. Sometimes, 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 with the electronic service tool installed 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. 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.
The ECM is limited to a maximum of 6 diagnostic or event codes (active or logged). New errors will not display until old errors are cleared.
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| Illustration 10 | g03799446 |
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Typical example | |
The primary speed sensor (1) is on the right-hand side of the engine towards the bottom of the flywheel housing.
The primary speed sensor generates a signal by detecting the movement of the flywheel. The signal that is generated by the speed sensor is transmitted to the ECM.
The ECM uses the signal from the speed sensor to determine the engine speed.
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| Illustration 11 | g03799448 |
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Typical example | |
The secondary speed sensor (2) is on the front of the engine towards the top of the front housing.
The secondary speed sensor generates a signal that is related to the position of the fuel injection pump. The secondary speed sensor detects the movement of the timing plate that is installed to the gear for the fuel injection pump. The signal that is generated by the speed 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 12 | g03838255 |
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Typical example | |
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| Illustration 13 | g03808660 |
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Typical example | |
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| Illustration 14 | g03834219 |
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Typical example | |
The boost pressure sensor is an active sensor.
The boost pressure sensor provides the ECM with a measurement of inlet manifold pressure.
The operating range of the boost pressure sensor is
The engine oil pressure switch provides the ECM with a measurement of engine oil pressure. 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 engine oil pressure switch is operated when a pressure of
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| Illustration 15 | g03808661 |
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Typical example | |
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| Illustration 16 | g03799762 |
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Typical example | |
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
The operating range for the inlet manifold temperature sensor is ...
The operating range for the coolant temperature sensor is ...
The operating range for the fuel temperature sensor is ...
The operating range for the DOC inlet and exhaust sensors is ...
The sensors are also used for engine monitoring.