Powertrain
generic / SAE
P25B5
Turbocharger/Supercharger Wastegate B Stuck Open
Same as wastegate A stuck open, applied to the second wastegate (twin-turbo, sequential or two-stage). Boost control tracks commanded vs. actual manifold pressure; persistent deviation means wastegate, vanes, hose or actuator are not delivering the requested pressure.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number5 / B5
Possible causes
- Seized wastegate linkage high
- Carbon or debris buildup preventing free movement low
- Component wear with age - mechanical play low
Symptoms
- Check engine light on
- Significant power loss / limp mode
- Possible blue or black smoke from exhaust
- Whistling or hissing sound from intake
Inspection / repair
- Difficulty: hard
- DIY: shop recommended
- Estimated cost: 400–2500 €
- Estimated time: 1.5–6 h
- Component: wastegate b
- Component: turbocharger b
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012