Cummins ISB6.7 CM2150 (2007-09) 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.

Verify the electronic control module (ECM) calibration is correct. Check the calibration revision history found on QuickServe® Online for applicable fixes to the calibration stored in the ECM. If necessary, recalibrate the ECM.

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.