OBD-II code · Powertrain (generic, extended)
P237D Exhaust Heat Exchanger Bypass Valve A Control Circuit Low
Same as P237C with the control line shorted to ground. 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.
Is it safe to drive with P237D?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyControl line shorted to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–2.5 h
- Emissions test
- Likely to fail
- Parts involved
- Exhaust Bypass Valve A, Exhaust Heat Recovery Actuator
Related codes
- P23A3Exhaust Heat Exchanger Bypass Valve B Control Circuit Low
- P237AO2 Sensor Exhaust Sample Error Bank 1 Sensor 2
- P237BO2 Sensor Exhaust Sample Error Bank 2 Sensor 2
- P237CExhaust Heat Exchanger Bypass Valve A Control Circuit Open
- P237EExhaust Heat Exchanger Bypass Valve A Control Circuit High
- P237FExhaust Heat Exchanger Bypass Valve A Control Performance
- P2380Wait to Start Lamp Control Circuit
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.