Faulty water-in-fuel sensor or sensor element contaminated with debris; Damaged or corroded wiring harness or connector at the sensor; Open or short circuit in the sensor signal or ground circuit; Water intrusion into the fuel filter housing or sensor connector; Failed fuel filter water separator assembly (internal sensor fault); PCM software issue or internal driver fault (rare)

DTC codes / P22xx · Fuel and air metering (injector circuits) / P2264

P2264Water in Fuel Sensor Circuit

Q: What does code P2264 mean?

Water in Fuel Sensor Circuit. P2264 indicates that the powertrain control module (PCM) has detected an abnormal condition in the water-in-fuel sensor circuit, which monitors for moisture contamination in the diesel fuel system. The sensor typically outputs a voltage or resistance signal that the PCM interprets; when the signal falls outside the expected range for a calibrated period, the code is stored.

P2264 indicates that the powertrain control module (PCM) has detected an abnormal condition in the water-in-fuel sensor circuit, which monitors for moisture contamination in the diesel fuel system. The sensor typically outputs a voltage or resistance signal that the PCM interprets; when the signal falls outside the expected range for a calibrated period, the code is stored.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

Symptoms you may notice

Illumination of the check engine light or a dedicated water-in-fuel warning lamp
Rough running or misfire if water has actually entered the fuel system
Reduced engine power or limp mode in some vehicles
Hard starting or stalling, especially after refueling
Often no symptoms besides the warning light when the sensor circuit alone is faulty

Common causes, most likely first

Faulty water-in-fuel sensor or sensor element contaminated with debris
Damaged or corroded wiring harness or connector at the sensor
Open or short circuit in the sensor signal or ground circuit
Water intrusion into the fuel filter housing or sensor connector
Failed fuel filter water separator assembly (internal sensor fault)
PCM software issue or internal driver fault (rare)

How to diagnose and fix it

Inspect the water-in-fuel sensor connector and wiring for corrosion, damage, or loose pins
Drain the fuel filter water separator according to the manufacturer's procedure and clear the code
Test the sensor resistance or voltage output with a multimeter and compare to specifications
Check continuity and voltage drop on the signal and ground circuits between the sensor and PCM
Replace the water-in-fuel sensor or fuel filter assembly if testing indicates a faulty component
Clear the code and verify the repair by running the engine and monitoring live data for the sensor signal

Water-in-Fuel Sensor Circuit Quirks

A common misdiagnosis is replacing the sensor when the real problem is water contamination in the fuel filter housing that has shorted the sensor element.
The water-in-fuel sensor often shares a ground with other sensors, so a bad ground can set P2264 along with other codes.
Some vehicles require a relearn or reset procedure after draining water from the filter, and skipping it will keep the code active.
The sensor may only set the code after a specific driving cycle, so a test drive may be needed before the code clears.
Aftermarket fuel filters with integrated sensors can have incompatible resistance values and cause repeat P2264 codes.

Can I keep driving with P2264?

If the only symptom is the warning light and the engine runs normally, you can drive cautiously to a service location, but avoid hard acceleration or towing. If the engine runs rough or loses power, stop driving and have the vehicle towed to prevent fuel system damage.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.