Cummins ISM CM870 (2003-06) Fault Code: 245 PID: S033 SPN: 647 FMI: 4/4 Fan Control Circuit – Voltage Below Normal or Shorted to Low Source. Low signal voltage detected at the fan control circuit when commanded ON.

This fault code is logged when the ECM commands 12 or 24-VDC to the fan control solenoid, but the voltage on the fan control signal circuit is less than 12 or 24-VDC. The low voltage on the signal circuit usually indicates a short circuit to ground in the harness or solenoid.

If Fault Code 245 is still active after completing the following troubleshooting steps, consult the OEM service manual for procedures to check the fan control circuit for a short circuit to ground.

For intermittent power supply and datalink communication issues with Aftertreatment Components, it is highly recommended that the OEM Power Distribution Center fuses and relays be thoroughly checked for loose, missing or intermittent connections.

Possible repair:

1)Replace the fan control solenoid.
2)Repair or replace the OEM harness.
3)Replace the ECM.