Powertrain
generic / SAE
P259E
Turbocharger A Boost Control Position At Low Limit
The boost-control actuator on turbo A has been operating at the low end of its travel for too long — the closed-loop controller is saturated against the lower stop trying to reach the boost setpoint. Indicates either a leak (wastegate held closed but boost still escapes) or commanded boost above what the engine can produce.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number5 / 9E
Possible causes
- Boost leak in the charge-air path high
- Failing turbocharger that cannot produce target boost medium
Symptoms
- Charge status indicator shows fault
- Charging may not start or interrupts
- Slower-than-expected charge rate
Inspection / repair
- Difficulty: hard
- DIY: shop recommended
- Estimated cost: 200–2500 €
- Estimated time: 0.8–5 h
- Component: turbo actuator a
- Component: boost control loop
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012