PACCAR PX-6 CM2150 (2007-09) Fault Code: 428 PID: 97 SPN: 97 FMI: 3 Water-in-Fuel Indicator Sensor Circuit – Voltage Above Normal or Shorted to High Source. High 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, calibrate the ECM.

Possible causes:

1)Open return or signal circuit in the harness, connectors, or sensor
2)Signal wire shorted to sensor supply or battery voltage.

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.