P2264: Water in Fuel Sensor Circuit

What it means

The ECU detects an electrical fault in the diesel water-in-fuel sensor circuit. Until repaired, water contamination in the fuel filter cannot be detected, risking damage to the high-pressure pump and injectors.

At a glance

• Usually lights the check-engine light

How it works

A water-in-fuel sensor detects water collected in the diesel fuel filter so the driver can drain it before it reaches the injection system. The module sets P2264 when it detects an electrical fault in the sensor circuit, which can leave water in the filter undetected.

Common causes

Most likely first.

1. Defective water-in-fuel sensor
2. Wiring or connector fault

Symptoms

• Check-engine light may illuminate
• Water-in-fuel warning may not function
• Usually no noticeable change in driving

How to diagnose it

1. Check freeze-frame data and scan-tool status to see whether the water-in-fuel circuit fault is current or intermittent.
2. Inspect the sensor at the diesel fuel filter and its connector for looseness, corrosion, moisture, or physical damage.
3. Trace the sensor wiring for breaks, chafing, or poor connections between the sensor and module.
4. Check circuit continuity and for unintended shorts using the vehicle wiring diagram and manufacturer's procedure.
5. Test the water-in-fuel sensor itself before replacing it, and verify that the warning responds correctly after repair.

Common fixes

• Reconnect a loose water-in-fuel sensor plug.
• Clean or repair corroded connector terminals.
• Repair damaged wiring in the sensor circuit.
• Replace the water-in-fuel sensor if circuit tests show it has failed.

Can I keep driving?

The vehicle may drive normally, but the water-in-fuel warning may not alert you to contamination that can damage the high-pressure pump and injectors. Have the fault repaired promptly and follow the vehicle's guidance if a water warning appears.