P2265: Water in Fuel Sensor A Circuit Range/Performance

P2265 means the signal from water-in-fuel sensor A is electrically present but does not behave plausibly, for example a self-test response that comes at the wrong time or a value that sits between the expected dry and wet states. No manufacturer documents P2265 publicly. A comparable check appears in GM's 2018 diesel tables under P2264: after a long ignition-off period the sensor has to signal water for a short moment right after power-up, and a missing response is judged as a fault. The probes measure conductivity between two electrodes in the water sump of the filter, so a film of dirt, biodiesel residue or a partly corroded probe can push the reading into an implausible zone. The code usually lights only a service or water warning; draining and cleaning come before replacing parts.

Low severity. Can I keep driving?You can normally keep driving. If it affects the fuel level, do not trust the gauge and refuel earlier than usual.

Symptoms

Water warning or service lamp that comes and goes
Water warning stays on even after the filter has been drained

Most likely causes

Sludge, emulsion or deposits coating the sensor electrodes
Sensor electronics drifting so the output lies between dry and wet
Corroded terminals adding resistance to the signal circuit

What to check, in order

Start with the simplest. You can tick off each step.

Check the connector and wiring
Compare the reading with other engine data while varying the engine speed.
Use live data to compare the reading with actual conditions
Measure power, ground, and signal
Replace the sensor if the circuit is good

Good to know

Repair difficulty: easy

What each character of P2265 means

P: Powertrain: engine and transmission
2: Generic code: same on every make
2: Fuel injection
65: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2265?

You can normally keep driving. If it affects the fuel level, do not trust the gauge and refuel earlier than usual.

What causes code P2265?

The most common causes are: sludge, emulsion or deposits coating the sensor electrodes; sensor electronics drifting so the output lies between dry and wet; corroded terminals adding resistance to the signal circuit.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.