P23A8Exhaust Heat Exchanger Exhaust Bypass Valve B 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
- P23A8 concerns the position feedback of exhaust bypass valve B at its mechanical end stops. Systems with a position sensor learn the readings at the fully open and the fully closed stop and compare later readings with them; if a stop value drifts out of its window, or the flap no longer reaches the stop at all, this code is set. Causes range from a carbon-fouled or bent flap to a slipping sensor or a worn actuator. No manufacturer documents P23A8; for valve A the equivalent is P25D6. Ford lists the valve A position sensor code P2C23 together with corroded exhaust coolant temperature sensor connectors (SSM 52543) and with a worn heat exchanger actuator (SSM 53003). CARB requires rationality checks on such inputs. Driveability normally stays unchanged.
- What you may notice
- Check engine light on
- Valve position in live data does not reach the expected end value
- Likely causes
- LikelyDeposits or a bent flap keep valve B from reaching its end stop
- PossiblePosition sensor in the actuator drifted or loose
- PossiblePlay in the actuator gearing
- RareEnd stops not relearned after a repair
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €0 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.