Circuit DescriptionThe water-in-fuel sensor is in the fuel filter. The engine control module (ECM) provides a 5 volt reference signal to the water-in-fuel sensor. When the water collected in the fuel filter covers the sensor probes, the water-in-fuel sensor pulls the 5 VDC reference voltage down, indicating high water accumulation in the fuel filter.

Component LocationThe water-in-fuel sensor is integrated into the bottom of the original equipment manufacturer (OEM) supplied suction fuel filter.

Conditions for Running the DiagnosticsThis diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running.

Conditions for Setting the Fault CodesThe ECM detected the water-in-fuel sensor signal voltage was out of range high.Action Taken When the Fault Code is ActiveThe ECM illuminates the white MAINTENANCE lamp or flashes the amber CHECK ENGINE lamp, indicating a maintenance condition, immediately when the diagnostic runs and fails.Conditions for Clearing the Fault CodeTo validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.The fault code status displayed by INSITE? electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.The ECM will turn off the flashing amber CHECK ENGINE lamp / white MAINTENANCE lamp immediately after the diagnostic runs and passes.The Reset All Faults command in INSITE? electronic service tool can be used to clear active and inactive faults, as well as extinguish the malfunction indicator lamp for on-board diagnostics applications.

Shop TalkPossible causes for this fault code include:

Open RETURN or SIGNAL circuit in the harness, connectors, or sensorSIGNAL wire shorted to sensor supply or battery voltage.

Possible Cause:1) Engine Harness2) ECM calibration