P0452EVAP System Pressure Sensor/Switch A Circuit Low
- 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. P0452 means its signal voltage is below the lower limit: GM below 0.15 V (640 of 800 samples, MIL after two trips), Ford below 0.1 V for 5 s, Saab below 0.1 V for more than 5 s. Common causes are a signal wire shorted to ground, an interrupted or shorted 5 V reference or a faulty sensor. Leak and purge 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 wire shorted to ground or connector corroded
- PossibleTank pressure sensor faulty internally
- Possible5 V reference open or shorted (shared reference)
- 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.