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Caterpillar C9 Engine 15 164-2 Injection Actuation Pressure Signal Erratic

The Engine Control Module(ECM) detects the following conditions:

The injection actuation pressure is greater than 3 MPa (435 psi) for more than three seconds when the engine is off.

The difference in the actual pressure and the desired pressure is greater than 2 MPa (290 psi) for more than ten seconds with the engine running.

Actual rail pressure is between 11.0 MPa (1595.41 psi) and 17.4 MPa (2523.66 psi) for more than ten seconds.

Sensor current changes more than0.075 Amp and rail pressure changes less than 0.5 MPa (72.5 psi) with the engine on.

The engine is not running and the ECM has been powered for at least four seconds.

Cold mode is not active.

 

Engine speed is 0 rpm for more than 3 seconds and the engine is not running.

The injection actuation pressure sensor measures the pressure of the oil in the high pressure oil manifold. The high pressure oil in the manifold is used to actuate the injectors and the high pressure oil is used to control the fuel injection pressure. Fuel injection pressure is based on inputs from the sensors. The inputs are used by the Engine Control Module (ECM) for calculating the fuel injection pressure. The ECM uses the reading from the injection actuation pressure sensor in order to control the operation of the injection actuation pressure control valve.

Caterpillar C9 Engine

Caterpillar CAT ET 2024A

CAT Comm Adapter 3

 

Probable Causes:

1) ECM Connection

2) Injection actuation pressure sensor

3) Injection actuation pressure sensor wiring/connection