P04C4Fuel Fill Door Lock Position Sensor/Switch Circuit Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- On plug-in hybrids with a sealed, pressurised tank, pressing the fuel button (open request) starts a refuelling mode: the module opens the tank valve, releases the pressure into the charcoal canister and only then unlocks the filler door via an electric actuator (Ford patent). The lock position sensor in the actuator reports locked or unlocked – not to be confused with the door position sensor (open or closed, P04B7–P04BA). P04C4 means its feedback is electrically valid but does not fit the commanded state – for example unlock commanded and the sensor still reports locked – or does not change. No manufacturer document available to us uses this code; the description follows CARB's rules for input and output components and patents on the door actuator.
- What you may notice
- Filler door does not unlock or lock reliably
- Refuelling system message
- Possibly check engine light
- Likely causes
- LikelyActuator does not travel fully (blocked or worn)
- PossibleSwitch in the actuator worn or misadjusted
- PossibleDoor distorted, latch does not engage
- RareModule
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €60 – €300
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.