P02CA
Turbocharger/Supercharger B Overboost Condition
Boost pressure on the secondary turbocharger/supercharger (B) on a sequential or twin-charged setup is above the upper threshold. Wastegate stuck closed, VGT vanes stuck, or boost pressure sensor reads high.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: hard
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.
- Wastegate stuck closedCommon
- VGT vanes stuck closedPossible
Parts involved
- Turbocharger B
- Wastegate B
- Boost Pressure Sensor B
P02CA 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.