P2598
Turbocharger Boost Control Position Sensor A Performance - Stuck Low
Position sensor A reports a value stuck near the low end of its travel even when the actuator is commanded to move. Either the actuator is mechanically stuck closed (wastegate jammed shut, VGT vanes seized at minimum opening) or the sensor itself is pegged low. Boost is uncontrolled — overboost on diesels with VGT, underboost on wastegate-stuck systems.
- 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 low endCommon
- Sensor pegged lowPossible
Parts involved
- Turbo Actuator Position Sensor A
- Turbo Actuator
P2598 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.