PACCAR PX-9 CM2350 (2013-17) Fault Code:294 PID:441 SPN:441 FMI:4 Auxiliary Temperature Sensor Input 1 Circuit – Voltage Below Normal or Shorted to Low Source

Reason:
Auxiliary Temperature Sensor Input 1 Circuit – Voltage Below Normal or Shorted to Low Source. Low signal voltage detected at the OEM auxiliary temperature circuit.

Effect:
None on performance

Circuit Description:
The original equipment manufacturer (OEM) has the option of wiring a temperature sensor input to the Cummins® engine control module (ECM). This input is intended for a variable resistance temperature sensor.

Component Location:
The OEM temperature sensor input and location will vary. Refer to the OEM service manual for sensor location.

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

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the OEM temperature signal circuit is out of range low.

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) Signal shorted to ground in the harness
2) Signal shorted to return or ground in the sensor