Powertrain
generic / SAE
P23A4
Exhaust Heat Exchanger Bypass Valve B Control Circuit High
Same as P237E on bypass valve B. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number3 / A4
Possible causes
- Control line shorted to supply high
- Connector pins corroded - high contact resistance low
- Supply wire pinched against B+ source low
Inspection / repair
- Difficulty: medium
- DIY: shop recommended
- Estimated cost: 200–700 €
- Estimated time: 1–2.5 h
- Component: exhaust bypass valve b
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012