Turbocharger/Supercharger B Underboost Condition
Boost pressure on the secondary turbocharger/supercharger (B) is below the lower threshold. Wastegate stuck open, charge-air leak, or VGT vanes stuck open.
Affected components
- Turbocharger b
- Wastegate b
- Charge air pipe
Common causes
- High likelihood: Wastegate stuck open
- Medium likelihood: Charge-air pipe leak
Possible symptoms
- Check engine light on
- Significant power loss / limp mode
- Possible blue or black smoke from exhaust
- Whistling or hissing sound from intake
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.