P04ADEVAP System Purge Control Valve B 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. Purge valve B is a second electric purge valve, usually for the high-load purge line of a turbo engine, which purges to the compressor inlet when there is boost in the manifold (Ford patent). Many makers solve this path with one purge valve and passive check valves instead – Ford tests it as P04F0 – and then have no valve B. CARB requires every purge path to be checked. P04AD means the control wire of purge valve B is shorted to positive: the valve cannot open and the driver may switch off for protection, so the canister is purged less under load. No manufacturer document available to us uses this code; the description follows CARB and the comparable purge valve A checks (for GM P0443/P0458/P0459).
- What you may notice
- Check engine light on
- EVAP readiness not set
- Usually no change in driving
- Likely causes
- LikelyControl wire touching battery positive
- PossibleCoil shorted internally (driver overcurrent)
- PossibleCorrosion in the connector
- RareDriver in the engine module
- 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: €40 – €250
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.