PACCAR PX-9 CM2350 (2013-17) Fault Code:3141 PID: SPN:3667 FMI:4 Engine Air Shutoff Circuit – Voltage Below Normal or Shorted to Low Source

Reason:
Engine Air Shutoff Sensor Circuit – Voltage Below Normal or Shorted to Low Source. Low signal voltage detected at the engine air shutoff circuit.

Effect:
The engine air shutoff valve will be disabled.

Circuit Description:
The air shutoff valve is an optional component used to shutdown the engine in the event of an engine overspeed condition. It can be closed via a manual shutdown switch or via an ECM command.

Component Location:
The engine air shutoff valve location can vary depending on the OEM. Refer to the OEM service manual.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the engine air shut off driver was shorted to ground.

Action Taken When the Fault Code is Active:
The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs and fails.

Conditions for Clearing the Fault Code:
1) To validate the repair, start the engine and let it idle for 1 minute.
2) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
3) The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
4) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults.

Shop Talk:
N/A

Possible Causes:
1) Short circuit to ground in the engine air shutoff circuit
2) Malfunctioning ECM