Cummins ISB4.5 CM2150 Fault Code: 435 PID: 100 SPN: 100 FMI: 2 Engine Oil Rifle Pressure – Data Erratic, Intermittent, or Incorrect.

Posted by PerDiezel Solutions on January 20, 2026

Circuit Description
The engine oil pressure switch is used by the electric control module (ECM) to monitor the lubricating oil pressure. The oil pressure switch is normally closed when the engine is not operating and open when the engine is in operation and oil pressure is present.

Component Location
The location of the oil pressure switch varies by engine model.

Conditions for Running the Diagnostics
This diagnostic runs when the keyswitch is turned ON and before engine speed is detected.

The diagnostic only runs once per trip.

Conditions for Setting the Fault Codes
The ECM detects that the engine oil pressure switch is indicating that oil pressure is present (switch is open) at intial key-ON for two consecutive key cycles, when the ECM expected to see no oil pressure (switch closed) at key-ON.

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 for the engine oil pressure reading is used.

Conditions for Clearing the Fault Code
-To validate the repair, perform a key cycle. Turn the key to the ON position but do not start the engine.
-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 the INSITE™ electronic service tool.

Possible Causes
-Damaged engine oil pressure switch
-Open circuit in the engine oil pressure switch signal wire
-Damaged ECM
-Short circuit in the enigne oil pressure switch signal wire to a voltage source.

Cummins ISB4.5 CM2150 Fault Code: 435 PID: 100 SPN: 100 FMI: 2 Engine Oil Rifle Pressure – Data Erratic, Intermittent, or Incorrect.

Cummins ISB4.5 CM2150 Fault Code: 429 PID: 97 SPN: 97 FMI: 4 Water-in-Fuel Indicator Sensor Circuit – Voltage Below Normal or Shorted to Low Source.

Cummins ISB4.5 CM2150 Fault Code: 428 PID: 97 SPN: 97 FMI: 3 Water-in-Fuel Indicator Sensor Circuit – Voltage Above Normal or Shorted to High Source.

Cummins ISB4.5 CM2150 Fault Code: 427 PID: SID 231 SPN: 639 FMI: 9 J1939 Data Link – Abnormal Update Rate.

Cummins ISB4.5 CM2150 Fault Code: 425 PID: 175 SPN: 612 FMI: 2 Engine Oil Temperature – Data Erratic, Intermittent, or Incorrect.

Cummins ISB4.5 CM2150 Fault Code: 418 PID: 97 SPN: 97 FMI: 0 Water-in-Fuel Indicator – Data Valid But Above Normal Operating Range – Least Severe Level.

WARNING!