Introduction
The engine supplies power to the ECM. The ECM powers the following components:
- All sensors on the engine
- The suction control valve for the fuel injection pump
- Diagnostic connector
- Electronic unit injectors
The glow plugs are powered directly from the battery.
ECM Power Supply
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| Illustration 1 | g03590180 |
Typical example of a schematic for the electrical power supply circuit | |
The power supply to the ECM and the system is drawn from the 24 V or the 12 V battery. The power supply for the ECM has the following components:
- Battery
- Disconnect switch
- Ignition keyswitch
- Fuses
- Ground bolt
- ECM connector
- Machine interface connector
The Schematic for the ECM shows the main components for a typical power supply circuit. Battery voltage is normally connected to the ECM. The input from the ignition keyswitch turns on the ECM.
The wiring harness can be bypassed for troubleshooting purposes.
The display screen on the electronic service tool can be used in order to check the voltage supply.
Power Supply for the Pressure Sensors
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| Illustration 2 | g03809244 |
Schematic for the pressure sensors on the P1 connector | |
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| Illustration 3 | g03809261 |
Schematic for the pressure sensors on the P2 connector | |
The ECM supplies 5 VDC through the ECM connector to each sensor. The power supply is protected against short circuits. A short in a sensor or a wiring harness will not cause damage to the ECM.
Power Supply for the Glow plugs
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| Illustration 4 | g03809297 |
Typical example of a schematic for the glow plug starting aid circuit | |
Power Supply for the MCS Control System
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| Illustration 5 | g03819764 |
Typical example of a schematic for the power supply for the MCS control system (1) Battery (customer supply) (2) DC main control power positive isolator switch (3) 20A circuit breaker (customer supply) (4) 20A circuit breaker (5) Relay (6) Quint diode (7) 10A circuit breaker (8) MCS generator set control unit (9) Electronic Control Module (ECM) | |