P23A7Exhaust Heat Exchanger Exhaust Bypass Valve B Stuck Closed
- 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
- P23A7 is the opposite of P23A6: the second bypass valve (B) on the exhaust heat exchanger does not open on command and stays closed. Depending on the layout, all exhaust is then forced through the heat exchanger even when the engine is fully warm, which adds heat to the coolant and some back pressure – most relevant under load and in hot weather. The module recognises the condition from position feedback or from temperatures that do not follow the command. No manufacturer publishes P23A7, and the valve A version is P00E4. Ford's valve A cases, water inside the heat exchanger (SSM 51921) and a replaceable actuator kit (SSM 53003), are the nearest public examples. CARB requires output components to be checked for proper function. Keep an eye on coolant temperature until it is repaired.
- What you may notice
- Check engine light on
- Coolant temperature higher than usual under load
- Possibly reduced power or a changed exhaust note
- Likely causes
- LikelyFlap stuck closed by deposits or corrosion
- PossibleActuator motor or gearing failed
- RareDamaged or water-filled heat exchanger obstructing the flap
- 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: €100 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.