P0453EVAP System Pressure Sensor/Switch A Circuit High
- 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. P0453 means its signal voltage is above the upper limit: GM above 4.85 V (640 of 800 samples, MIL after two trips), Ford and Saab 9-4X above 4.9 V for 5 s. Ford states explicitly that an open circuit sets P0453, because the module's pull-up then drives the signal high. Other causes are a short to 5 V or battery voltage. 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
- LikelySignal or ground wire open, connector off
- PossibleTank pressure sensor faulty
- RareSignal shorted to 5 V or battery voltage
- RareEngine module
- 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.