Cummins ISC CM2150 (2007-09) Fault Code: 529 PID: SID 051 SPN: 703 FMI: 3 Auxiliary Input/Output 3 Circuit – Voltage Above Normal or Shorted to High Source. High signal voltage has been detected at the auxiliary input/output 3 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.

The ECM monitors the voltage level on this circuit. When the ECM commands the OEM output signal low, it expects the voltage level to be approximately 0-VDC. If it detects a high voltage, this fault is recorded. If Fault Code 529 is still active after completing the following troubleshooting steps, refer to the OEM troubleshooting and repair manual for procedures to check the OEM output device for an open circuit or short circuit to ground.

Possible causes:

1)Open circuit in the engine harness or OEM output control solenoid
2)Short circuit to voltage source in the OEM harness
3)Malfunctioning ECM.

Possible repairs:

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