Cummins ISB CM850 (2003-06) Fault Code: 294 PID: 441 SPN: 441 FMI: 4 Auxiliary Temperature Sensor Input 1 Circuit – Voltage Below Normal, or Shorted to Low Source. Low signal voltage detected at OEM auxiliary temperature circuit.

Cummins ISB CM850 (2003-06) Fault Code: 294 PID: 441 SPN: 441 FMI: 4 Auxiliary Temperature Sensor Input 1 Circuit – Voltage Below Normal, or Shorted to Low Source. Low signal voltage detected at OEM auxiliary temperature circuit.

Possible causes:

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

Possible repairs:

1)Replace the OEM temperature sensor.
2)Repair or replace the OEM harness.
3)Replace the ECM.