P2264 – Water in Fuel Sensor Circuit

System: Powertrain | Standard: ISO/SAE Controlled | Fault type: General

Definition source: SAE J2012/J2012DA (industry standard)

DTC P2264 indicates a problem in the water in fuel sensor circuit. This code is set when the powertrain control module detects an electrical issue affecting the sensor circuit responsible for signaling the presence of water contamination in fuel. Because sensor design, circuit strategy, and enabling conditions vary by vehicle, the exact trigger thresholds and related symptoms can differ. Always confirm the code’s setting criteria, circuit pinout, and test specifications using the correct service information for the vehicle you are working on before beginning diagnosis.

What Does P2264 Mean?

P2264 – Water in Fuel Sensor Circuit means the control module has identified a fault within the electrical circuit for the water-in-fuel sensing system. Per SAE J2012 DTC structure conventions, this is a standardized powertrain code with an ISO/SAE-controlled meaning, and it points you toward circuit integrity and signal validity checks for the water-in-fuel sensor and its related wiring. The code does not, by itself, prove that water is present in the fuel; it indicates the sensor circuit is not operating as expected.

Quick Reference

  • System: Powertrain
  • Official meaning: Use the official definition provided by the data source for this code.
  • Standard: ISO/SAE controlled
  • Fault type: Circuit
  • Risk level: Moderate; the warning may be unreliable and fuel contamination protection strategies may be affected.

Symptoms

  • Warning light: Check Engine Light illuminated
  • Message/indicator: Water-in-fuel warning displayed or warning lamp may illuminate (if equipped)
  • Driveability: Reduced performance or hesitation may be present on some vehicles
  • Starting: Extended crank or hard start may occur depending on strategy
  • Idle quality: Rough idle may be noticed in some cases
  • Fuel system mode: Limited-power or protective fueling strategy may be triggered (varies by vehicle)
  • Intermittency: Symptoms may come and go with vibration, moisture, or temperature changes

Common Causes

  • Water in fuel sensor circuit wiring damage (chafed, pinched, or heat-damaged harness)
  • Loose, corroded, or fluid-contaminated connector at the water in fuel sensor
  • Poor terminal fit (spread pins) causing intermittent contact in the sensor connector
  • Open circuit in the signal, reference, or ground path between the sensor and control module
  • Short to ground or short to power within the sensor circuit (varies by vehicle design)
  • Faulty water in fuel sensor (internal electrical fault or out-of-spec output)
  • Ground path resistance too high (shared ground point corrosion or loose fastener)
  • Power supply issue to the sensor circuit (missing reference voltage or fused feed, as applicable)
  • Control module input fault for the water in fuel sensor circuit (less common)

Diagnosis Steps

Tools you’ll typically need include a scan tool capable of viewing live data and freeze-frame, a digital multimeter, and basic backprobing leads. A wiring diagram and connector pinout for the water in fuel sensor circuit are essential because sensor type and reference/ground strategy varies by vehicle. If available, use a test light or load tool to verify power/ground under load.

  1. Confirm the DTC is present and current. Record freeze-frame data and all stored and pending codes. If other powertrain or sensor-supply codes are present, diagnose those first because they can affect the water in fuel sensor circuit.
  2. Check the scan tool data list for the water in fuel sensor input (naming varies by vehicle). Note whether the reading is fixed, implausible, or intermittent. Clear the code and see if it resets immediately (key on) or only during engine operation or a road test.
  3. Perform a targeted visual inspection of the sensor, harness routing, and connector. Look for rubbed-through insulation, contact with sharp brackets, signs of fuel/water contamination at the connector, bent pins, or poor connector locking.
  4. Wiggle test: with the engine idling or key on (as applicable), monitor the sensor PID and gently manipulate the harness and connector. If the reading spikes or drops or the code sets, isolate the affected section and inspect for broken conductors or terminal issues.
  5. Verify sensor supply and ground. Using the wiring diagram, backprobe the sensor connector to check for the correct reference voltage or power feed and a solid ground. If ground is suspect, measure voltage drop between the sensor ground pin and battery negative with the circuit powered; excessive drop indicates high resistance in the ground path.
  6. Check the signal circuit integrity. With the connector attached, measure signal voltage at the sensor and compare it to the same signal at the control module pin (backprobe). A difference suggests resistance or a partial open between the sensor and module.
  7. Check for shorts to ground/power. With the ignition off and connector(s) unplugged (as directed by service info), measure resistance from the signal wire to ground and to power/reference circuits. Readings indicating continuity where none should exist point to a shorted harness or connector contamination.
  8. Perform a continuity and pin-to-pin test of the harness. With both ends disconnected, verify continuity for signal, power/reference, and ground circuits end-to-end. Also check for intermittent opens by flexing the harness while monitoring the meter.
  9. If wiring and connector tests pass, test the sensor per service information. Depending on design, this may include verifying a specified resistance range, frequency/duty-cycle output, or voltage response. Replace the sensor only if it fails the specified test.
  10. If the sensor tests good and the circuit integrity checks are normal, verify control module input behavior per service procedures. This may include checking for proper terminal tension at the module connector and confirming no water intrusion or corrosion at the module connector before considering module-level faults.

Professional tip: Use freeze-frame conditions to reproduce the fault, then log the water in fuel sensor PID along with sensor supply/reference voltage and ground voltage drop. Intermittent circuit issues often appear as brief PID dropouts or abrupt steps that coincide with harness movement or specific vibration/temperature conditions, helping you pinpoint the exact section to repair.

Possible Fixes

  • Repair wiring/connector issues: Clean corrosion, dry moisture intrusion, reseat terminals, and repair or replace damaged wiring in the water-in-fuel sensor circuit as confirmed by testing.
  • Restore power and ground integrity: Repair opens, high resistance, or poor ground points; correct pin fitment issues; and address any blown fuses or faulty relays that feed the sensor circuit (varies by vehicle).
  • Replace the water-in-fuel sensor: If circuit power/ground and signal wiring test good but the sensor output remains incorrect or unstable, replace the sensor per service information.
  • Service water-contaminated fuel concerns: If water is present where the sensor is installed, drain/clean the separator or filter housing as applicable and replace the fuel filter element if required by the procedure.
  • Address module-side connector faults: If proven by pin-to-pin tests, repair the control module connector, terminals, or harness interface that carries the sensor signal.
  • Update or reprogram control module (if applicable): Only if service information confirms a calibration update related to water-in-fuel sensor circuit diagnostics and all physical faults are ruled out.

Can I Still Drive With P2264?

Driving with P2264 may be possible in the short term, but it depends on how the vehicle reacts and whether water contamination is actually present. If you notice reduced power, hesitation, stalling, a no-start condition, or a warning message related to fuel quality, do not continue driving—have the vehicle inspected and the fuel system checked for water. If the vehicle drives normally, limit driving, avoid heavy loads, and schedule diagnosis soon, since prolonged operation with an active sensor circuit fault can prevent timely detection of fuel contamination.

What Happens If You Ignore P2264?

Ignoring P2264 can lead to repeated warning lights and reduced ability to detect or respond to water contamination in the fuel system (where equipped). If water is present and goes unaddressed, drivability may worsen and the risk of fuel system damage can increase. Even if no contamination exists, leaving an electrical circuit problem unresolved can lead to intermittent faults, unexpected changes in engine operation depending on strategy, and more difficult troubleshooting later due to compounded wiring or connector degradation.

Related Codes

  • P2267 – Water in Fuel Sensor Circuit High
  • P2266 – Water in Fuel Sensor Circuit Low
  • P2265 – Water in Fuel Sensor Circuit Range/Performance
  • P2230 – Barometric Pressure Circuit Intermittent
  • P2229 – Barometric Pressure Circuit High
  • P2228 – Barometric Pressure Circuit Low
  • P2227 – Barometric Pressure Circuit Range/Performance
  • P2226 – Barometric Pressure Circuit
  • P2299 – Brake Pedal Position / Accelerator Pedal Position Incompatible
  • P2296 – Fuel Pressure Regulator 2 Control Circuit High

Key Takeaways

  • P2264 is a circuit-related fault: Focus diagnosis on the water-in-fuel sensor circuit wiring, connectors, power, ground, and signal integrity.
  • Verify before replacing parts: Confirm circuit power/ground and signal behavior with tests rather than guessing.
  • Inspect for moisture and corrosion: Water intrusion at connectors or the sensor area is a common contributor and can create intermittent issues.
  • Driving may be limited: If drivability issues occur or water contamination is suspected, stop driving and arrange service.
  • Fix the verified cause only: Repairs should follow measured results (voltage drop, continuity, and signal checks) and service information.

FAQ

Does P2264 always mean there is water in the fuel?

No. P2264 indicates a fault in the water-in-fuel sensor circuit. Water contamination may be present, but the code can also set due to wiring damage, poor terminal contact, corrosion, power/ground issues, or a faulty sensor. Confirm with inspection and circuit tests.

What should I check first when diagnosing P2264?

Start with a visual inspection of the sensor and harness area for damaged wiring, loose connectors, corrosion, or moisture intrusion. Then verify the circuit’s power and ground are correct and stable, followed by checking the sensor signal circuit for opens, shorts, or abnormal readings.

Will clearing the code fix P2264?

Clearing the code only resets stored data; it does not correct the underlying circuit fault. If the problem remains, P2264 will typically return after the vehicle runs its self-tests or when the fault condition is detected again.