P23A2Exhaust Heat Exchanger Exhaust Bypass Valve B Control Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P23A2 reports an open or otherwise broken drive circuit for the second exhaust bypass flap, valve B, of an exhaust heat exchanger. Such units route the exhaust through a coolant heat exchanger after a cold start and send it past once engine and cabin are warm; a valve B only exists where the layout needs two flaps. No manufacturer documents P23A2 publicly. The closest published case is Ford's valve A on its full hybrids: SSM 51921 (Maverick 2.5L) and SSM 52050 (F-150 3.5L PowerBoost) treat the matching code P237C with a lit MIL and a new heat exchanger or muffler inlet pipe. CARB requires emission-related output components to be checked for circuit faults. P23A3 and P23A4 narrow the fault to low or high; P237C is valve A.
- What you may notice
- Check engine light on
- Slower engine and cabin warm-up in cold weather
- No change in how the vehicle drives
- Likely causes
- LikelyConnector at the valve B actuator loose, corroded or unplugged
- PossibleControl wire broken near the hot exhaust or at a harness clip
- PossibleActuator coil or internal electronics of valve B open
- 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: €50 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.