CM850 Electronic Control System – 019-043   Engine Wiring Harness

The engine uses three separate wiring harnesses to control the engine and some of the vehicle operations. Shown, left to right, are the ECM ports for the following:

1. 4-pin OEM power supply harness connector
2. 60-pin engine harness connector
3. 50-pin OEM harness connector.

Remove the harness clamps from the engine block.

Disconnect the engine harness from the injector pass-through connectors.

Disconnect the 60-pin engine harness connector from the ECM.

Disconnect the 4-pin power supply harness connector from the ECM.

Disconnect the electronic fuel control actuator from the engine harness.

Disconnect the engine harness from the following :

• Crankshaft position sensor. Refer to Procedure 019-365.
• Camshaft position sensor. Refer to Procedure 019-363.
• Intake manifold pressure sensor. Refer to Procedure 019-061.
• Intake manifold temperature sensor. Refer to Procedure 019-059.
• Barometric pressure sensor. Refer to Procedure 019-004, (this applies to automotive and industrial only).
• Oil pressure switch. Refer to Procedure 019-066.
• Engine coolant temperature sensor. Refer to Procedure 019-019.
• Turbocharger speed sensor. Refer to Procedure 019-390,
  (this applies to automotive and industrial only).
• Turbocharger compressor inlet temperature sensor. Refer to Procedure 019-395, (this applies to automotive and industrial only).
• Turbocharger control valve. Refer to Procedure 019-388, (this applies to automotive and industrial only).
• Rail fuel pressure sensor. Refer to Procedure 019-115.
• Water-in-fuel sensor. Refer to Procedure 019-127.
• Fuel lift pump.

Replace or repair the engine harness if there is an open circuit or a short circuit found under the protective covering of the harness body.

Connect the engine harness to the following:

• Crankshaft position sensor. Refer to Procedure 019-365.
• Camshaft position sensor. Refer to Procedure 019-363.
• Intake manifold pressure sensor. Refer to Procedure 019-061.
• Intake manifold temperature sensor. Refer to Procedure 019-059.
• Barometric pressure sensor. Refer to Procedure 019-004, (this applies to automotive and industrial only).
• Oil pressure switch. Refer to Procedure 019-066.
• Engine coolant temperature sensor. Refer to Procedure 019-019.
• Turbocharger speed sensor. Refer to Procedure 019-390,
  (this applies to automotive and industrial only).
• Turbocharger compressor inlet temperature sensor. Refer to Procedure 019-395, (this applies to automotive and industrial only).
• Turbocharger control valve. Refer to Procedure 019-388, (this applies to automotive and industrial only).
• Rail fuel pressure sensor. Refer to Procedure 019-115.
• Water-in-fuel sensor. Refer to Procedure 019-127.
• Fuel lift pump.

Connect the electronic fuel control actuator connector.

Connect the 60-pin engine harness connector to the ECM.

Connect the engine harness to the injector pass-through connectors.

Connect the 4-pin OEM power supply harness connector to the ECM.

Install the harness clamps that hold the engine harness to the engine block.