P2408Fuel Cap Sensor/Switch Circuit
- 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
- P2408 is the general circuit code for a sensor or switch that tells the engine computer whether the fuel cap or filler is closed. It is set when that circuit shows a fault not narrowed down to low, high, plausibility or dropout, which are P2410, P2411, P2409 and P2412. No manufacturer publicly documents this code; most systems infer the cap state from pressure instead. Ford's OBD summary, for example, detects a missing or loose cap (P0457) when the tank does not pull down past -8 inH2O within 30 s after refuelling, lights a Check Fuel Cap lamp and shows a capless-filler message. CARB lets makers skip the MIL for a detected cap leak if a separate warning lamp exists. The vehicle drives normally; the cap and wiring should be checked.
- What you may notice
- Check engine light or fuel cap warning
- EVAP leak test may be skipped
- Likely causes
- LikelyFaulty fuel cap or filler switch
- PossibleDamaged wiring or connector at the filler neck
- RareAftermarket cap that does not actuate the switch correctly
- 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: €20 – €200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.