Cummins ISL CM850 (2003-06) Fault Code: 135 (Auto) PID: 100 SPN: 100 FMI: 3 Oil Pressure Sensor Circuit – Voltage Above Normal, or Shorted to High Source. High signal voltage detected at the engine oil pressure circuit.

Cummins ISL CM850 (2003-06) Fault Code: 135 (Auto) PID: 100 SPN: 100 FMI: 3 Oil Pressure Sensor Circuit – Voltage Above Normal, or Shorted to High Source. High signal voltage detected at the engine oil pressure circuit.

The oil pressure sensor shares supply and return wires in the engine harness with other sensors. Opens and shorts in the engine harness can cause multiple fault codes to be active. Before troubleshooting Fault Code 135, check for multiple faults.

Possible causes:

1)Open return circuit in the harness, connectors, or sensor
2)Signal circuit shorted to sensor supply or battery voltage.

Possible repairs:

1)Replace the oil pressure sensor.
2)Replace the ECM.
3)Replace the engine harness.