P237C
Exhaust Heat Exchanger Bypass Valve A Control Circuit Open
Exhaust Heat Exchanger Bypass Valve A Control Circuit Open: the control circuit is open. Likely a broken wire, disconnected connector, or failed actuator.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Open in harness or connectorCommon
- Actuator solenoid or motor winding openPossible
- Pin pushed back out of connector bodyLess likely
Parts involved
- Exhaust Heat Exchanger
- Exhaust Bypass Valve A
- Exhaust Heat Recovery Actuator
P237C is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.