P25D6Exhaust Heat Exchanger Exhaust Bypass Valve A Position Sensor Stop Performance
- 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
- An exhaust heat exchanger moves exhaust heat into the coolant after a cold start; a flap (bypass valve A) decides whether gas flows through it or around it, and a position sensor reports where the flap is. P25D6 targets the end-stop values of that sensor: at the fully open and fully closed stops the reading must sit inside a learned or calibrated window. If a stop is no longer reached, or the stop value has shifted, the code is set. No manufacturer documents P25D6 publicly; the B-side twin is P23A8. The closest documented case is Ford's general valve A position sensor performance code P2C23 on full hybrids (F-150, Explorer, Escape, Maverick), where SSM 52543 first checks the exhaust coolant temperature sensor connectors and SSM 53003 replaces a worn actuator. Driving usually feels normal; warm-up may slow.
- What you may notice
- Check engine lamp on without noticeable driving change
- Slower engine warm-up or weaker cabin heat in winter
- Likely causes
- LikelyCarbon build-up or a bent flap stopping short of its end stop
- PossibleWorn valve actuator or linkage play
- PossiblePosition sensor shifted on its mount or drifting
- RareEnd stops not relearned after parts replacement
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €150 – €1,800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.