P2264: Water in Fuel Sensor A Circuit
What to do
The car drives normally. What has been lost is the warning that water is collecting in the fuel filter, which is worth having on a diesel — so until it is repaired, ask for the filter's water trap to be drained at every service. The sensor sits at the lowest point of the filter housing where water and corrosion collect, so ask for the connector to be inspected before the part is replaced.
What this code means
A fault in the circuit of the water-in-fuel sensor — a pair of contacts in the bottom of the diesel filter housing that detect water by conductivity, since diesel does not conduct and water does.
A circuit fault here is not itself damaging, but it removes a warning that protects something expensive. What that warning is for is set out at P2269: diesel fuel is the only lubricant the high-pressure injection pump receives, so water reaching it causes rapid wear whose debris then travels into the injectors. This sensor exists to catch that while it is still free to fix.
So the practical consequence of leaving this unrepaired is that the vehicle loses its ability to tell you about water, not that it has water. In the meantime, draining the filter's water trap manually at each service — or more often, on a vehicle whose fuel quality is uncertain — restores the protection the sensor was providing.
The sensor sits at the lowest point of the fuel filter housing, which is where water, dirt and corrosion all collect, so a corroded connector is the leading cause and is often visible.
Likely causes
Start here
- Corroded or loose connector · easy
- Faulty water in fuel sensor · easy
- Damaged wiring harness · moderate
Less common
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
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