P23A6Exhaust Heat Exchanger Exhaust Bypass Valve B Stuck Open
- 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
- P23A6 says that bypass valve B of the exhaust heat exchanger stays open while the module wants it closed. In the usual layout the exhaust then keeps taking the bypass route, so the heat exchanger adds little or no heat after a cold start – noticeable as a slow engine warm-up and a weak cabin heater in cold weather, and on hybrids as the engine running longer just to make heat. The fault is judged mechanically, from position feedback or temperature response, not from the wiring. No manufacturer documents P23A6; the valve A twin is P00E3. Ford's valve A bulletins (SSM 52050, SSM 53003) show that faulty bypass valves and worn actuators on these units do occur. CARB requires functional monitoring of such outputs. P23A7 is the reverse case.
- What you may notice
- Check engine light on
- Engine and heater take noticeably longer to warm up
- Hybrid engine runs more often in cold weather
- Likely causes
- LikelyFlap seized in the open position by carbon or corrosion
- PossibleLinkage between actuator and flap broken or detached
- PossibleActuator no longer able to move 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.