P2C2D
Turbocharger/Supercharger Bypass Valve B Position Exceeded Learning Limit
The turbocharger/supercharger bypass valve B reports a position exceeded learning limit condition. Boost recirculation cannot be commanded reliably on this branch.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light on
- Significant power loss / limp mode
- Possible blue or black smoke from exhaust
- Whistling or hissing sound from intake
Common causes
Ordered by how often each turns out to be the cause.
- Mechanism worn at end-stopsCommon
- Sensor reference driftedPossible
Parts involved
- Turbo Bypass Valve B
- Wiring Harness
- ECM
P2C2D 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.