P2D1A
Exhaust Flow Control Valve C Position Circuit High
The exhaust flow control valve C reports a position circuit high condition. Exhaust routing for back-pressure or noise control on this branch cannot be commanded reliably.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Signal wire shorted to B+Common
- Open position sensorPossible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- Exhaust Flow Control Valve C
- Wiring Harness
- ECM
P2D1A 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.