Cummins ISB4.5 CM2150 Fault Code: 135 PID: 100 SPN: 100 FMI: 3 Engine Oil Rifle Pressure 1 Sensor Circuit – Voltage Above Normal or Shorted to High Source.

Circuit Description
The engine control module (ECM) provides a 5 volt supply to the engine oil pressure switch on the sensor supply circuit. The ECM also provides a ground on the switch return circuit. The engine oil pressure switch provides a signal to the ECM on the engine oil pressure switch signal circuit. This switch signal voltage changes, based on the pressure in the oil rifle. The ECM will detect a low signal voltage at operating conditions when the oil pressure may be slightly lower.

Component Location
The engine oil pressure switch is located on the left side of the engine block.

Conditions for Running the Diganostics
This diagnostic runs continuously when the keyswitch is in the ON position.

Conditions for Setting the Fault Codes
The ECM detects that the engine oil pressure signal voltage is greater than .25 VDC for more than 16 seconds.

Action Taken When the Fault Code is Active
-The ECM illuminates the amber CHECK ENGINE light immediately when the diagnostic runs and fails.
-A default value of the engine oil pressure reading is used.

Conditions for Clearing the Fault Code
-To validate the repair, start the engine and let it idle for 1 minute.
-The ECM will turn off the amber CHECK ENGINE light and the fault code will go inactive immediately after the diagnostic runs and passes.
-This fault code can also be cleared with INSITE™ electronic service tool.

Shop Talk
If the oil pressure switch 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
-Open return circuit in the harness, connectors, or switch
-A signal circuit shorted to sensor supply or battery voltage.