PACCAR PX-8 CM2150 (2007-09) Fault Code: 429 PID: 97 SPN: 97 FMI: 4 Water-in-Fuel Indicator Sensor Circuit – Voltage Below Normal or Shorted to Low Source. Low voltage detected at the water-in-fuel 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 circuit shorted to ground in the harness, sensor, or connector.

Possible repairs:

1)Clean the connector and pins.
2)Replace the water-in-fuel sensor.
3)The removal and installation of the connector may correct the fault.
4)Repair or replace the engine harness.
Replace the ECM.