P2265 indicates the powertrain control module (PCM) has detected a signal from the water-in-fuel sensor that is outside the expected range or does not change as anticipated during normal operation. This sensor monitors the water separator/fuel filter for excess water accumulation.
The sensor element itself is the most common failure point, often due to internal corrosion or contamination from prolonged exposure to fuel and water.
Corroded, loose, or damaged wiring and connectors at the sensor or along the harness can create an open, short, or high-resistance condition.
If the water separator is full, the sensor may report a continuous high-water condition that the PCM interprets as a circuit performance fault.
High water content from bad fuel, or use of gasoline in a diesel system, can trigger a genuine high-water signal that mimics a sensor fault.
A control module issue is rare; it should be considered only after sensor, wiring, and fuel-condition causes have been ruled out.
Almost never. The PCM is the last item to suspect; the sensor, wiring, or actual water contamination cause this code in the vast majority of cases.
Short distances are usually safe, but prolonged operation risks fuel system damage from water and may trigger reduced-power mode.
Clearing only turns off the light; the code will return if the underlying sensor, wiring, or water-contamination issue is not resolved.
On many applications the sensor threads into the filter housing and can be replaced independently; on others it is integrated and requires housing replacement.