P04B6Fuel Fill Door Stuck Closed
- 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
- Plug-in and some full hybrids keep the fuel tank sealed while driving, separated from the charcoal canister by a valve. When the driver presses the fuel button, the system opens the valve, lets the pressure escape into the canister and only then unlocks the filler door. A switch reports whether the door is open or closed, so that the tank can be sealed again afterwards. P04B6 means that after a refuelling request and unlock command the switch still reports closed – the door does not open. According to the Ford patents the door is only released once tank pressure is below a threshold, so a valve that does not depressurise the tank has the same effect. On the 2026 Jeep Cherokee 1.6 hybrid P04B6 was stored without warning lamp as a software false trigger and is disabled by a reflash. Refuelling is then only possible via the emergency release.
- What you may notice
- Filler door does not open despite pressing the button
- Code often stored without warning lamp (Jeep)
- Refuelling only via emergency release
- Likely causes
- LikelyDoor latch, magnet or actuator blocked or faulty (ice, dirt, corrosion)
- PossibleDoor housing distorted after fitting, door jams
- PossibleTank cannot be depressurised (valve stuck closed, line blocked)
- RareSoftware false trigger
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €0 – €300
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.