Engine and gearbox (P)
P003B: Turbo/Supercharger Boost Control Limit Exceeded
The control module has detected that the turbocharger or supercharger boost control has exceeded its learning limit. This affects the boost-pressure control.
Checked by a licensed car technician · last reviewed 30 September 2026
Symptoms
- Reduced engine power
- Check engine light on
- Poor acceleration
- Possible whistling noise
Common causes
- Actuator B worn or sticking
- Faulty boost pressure sensor
- Vacuum leaks
- Faulty turbocharger or supercharger
How to check it yourself
- Inspect actuator B for wear or sticking
- Check for vacuum leaks
- Test the boost pressure sensor
- Inspect the turbocharger or supercharger
Can I keep driving?
The car can be driven, but performance may be reduced.
General guidance, not a professional inspection. Confirm faults with measurements before buying parts, and use a qualified mechanic for brakes, steering, fuel leaks, airbags, and other safety-critical work. Terms and disclaimer