Circuit DescriptionThe water-in-fuel sensor is attached to the fuel filter. The water-in-fuel sensor sends a signal to the ECM when a set volume of water has accumulated in the fuel filter. The water-in-fuel circuit contains two wires, a ground wire and a signal wire.

Component LocationThe water-in-fuel sensor is integrated into the bottom of the fuel filter. The filter housing location will vary with each OEM.

Conditions for Running the DiagnosticsThis diagnostic runs continuously when the engine is running.

Conditions for Setting the Fault CodesWater has been detected in the fuel filter housing above the warning limit.

Action Taken When the Fault Code is ActiveThe ECM illuminates the amber CHECK ENGINE light and/or the Malfunction Indicator Lamp (MIL) immediately when 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 diagnostic runs and passes.The ECM will turn off the amber CHECK ENGINE 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 TalkWater in the fuel can do extensive damage to the fuel system, due to the tight tolerances of the fuel system components.

The fuel filter must be drained immediately.

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