P04C8
Fuel Fill Door Open Request Sensor or Switch Circuit
A general circuit fault is detected on the open-request input - the button or switch the driver presses to release the fuel fill door. The ECU loses the request signal, so motorised release becomes unavailable.
- Check engine light: Not always
- Emissions related: No
- Repair difficulty: easy
Common causes
Ordered by how often each turns out to be the cause.
- Open in switch circuitCommon
Parts involved
- Fuel Fill Door Request Switch
P04C8 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.