Circuit DescriptionThe water-in-fuel sensor is attached to the fuel filter. The electronic 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 to ground, indicating high water accumulation in the fuel filter.

Component LocationThe water-in-fuel sensor is integrated into the bottom of the OEM supplied suction fuel filter.

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

Conditions for Setting the Fault CodesThe ECM detects that water in the fuel filter is above the sensor level.

Action Taken When the Fault Code is ActiveThe ECM flashes the amber CHECK ENGINE lamp indicating a maintenance condition immediately after the diagnostic runs and fails.Conditions for Clearing the Fault CodeTo validate the repair, 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 water has been drained from the fuel filter and the diagnostic runs and passes.The ECM will turn off the flashing amber MAINTENANCE lamp 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.

Shop TalkThis fault code indicates that water has been detected in the water separation fuel filter. Drain the water from the fuel filter.

If this fault code is active and there is no water in the fuel filter, a malfunctioning Water-In-Fuel sensor is a likely cause.

Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.

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 Cause:1) ECM calibration