P0450EVAP System Pressure Sensor/Switch A 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
- The evaporative emission (EVAP) system stores fuel vapour from the tank in a charcoal canister; a purge valve lets the engine draw it off, and a vent valve opens the canister to fresh air. The tank pressure sensor measures small pressures around ambient for the leak tests. Its direction differs by maker – on GM vacuum raises the voltage, on Ford and Bosch pressure does – so low and high refer to the signal voltage only. P0450 is the general circuit fault of tank pressure sensor A; makers that separate the fault use P0452 or P0453. Only Audi (2022/23) is documented with the code, as an electrical fault of the tank ventilation pressure sensor; GM, Ford and Saab do not use it. The leak tests are then suspended.
- What you may notice
- Check engine light on
- EVAP readiness not set, emission inspection not passed
- No change in driving
- Likely causes
- LikelyConnector at the tank pressure sensor corroded or loose (underbody, splash water)
- PossibleTank pressure sensor faulty
- PossibleDamaged 5 V, ground or signal wire
- RareEngine module software
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €40 – €250
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.