OBD-II code · Powertrain (generic, extended)
P25B6 Turbocharger/Supercharger Wastegate B Stuck Closed
Same as wastegate A stuck closed, applied to the second wastegate. Boost control tracks commanded vs. actual manifold pressure; persistent deviation means wastegate, vanes, hose or actuator are not delivering the requested pressure.
Is it safe to drive with P25B6?
Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.
Common causes
- Most likelyCarbon-locked wastegate flap
- Less likelyCarbon or debris buildup preventing free movement
- Less likelyComponent wear with age - mechanical play
Symptoms
- Check engine light on
- Significant power loss / limp mode
- Possible blue or black smoke from exhaust
- Whistling or hissing sound from intake
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1.5–6 h
- Emissions test
- Likely to fail
- Parts involved
- Wastegate B, Turbocharger B
Related codes
- P25B4Turbocharger/Supercharger Wastegate A Stuck Closed
- P25B3Turbocharger/Supercharger Wastegate A Stuck Open
- P25B5Turbocharger/Supercharger Wastegate B Stuck Open
- P25B7Auxiliary Ignition Switch On/Start Position Circuit
- P25B8Auxiliary Ignition Switch On/Start Position Circuit Low
- P25B9Auxiliary Ignition Switch On/Start Position Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.