P259B
Turbocharger Boost Control Position Sensor B Performance - Stuck High
Same as the A-side stuck-high fault, applied to sensor B / turbo B. Boost control tracks commanded vs. actual manifold pressure; persistent deviation means wastegate, vanes, hose or actuator are not delivering the requested pressure.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: hard
Symptoms
- Charge status indicator shows fault
- Charging may not start or interrupts
- Slower-than-expected charge rate
Common causes
Ordered by how often each turns out to be the cause.
- Actuator mechanically stuck near high endCommon
Parts involved
- Turbo Actuator Position Sensor B
- Turbo Actuator B
P259B 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.