What it means
Position sensor A reports a value stuck near the high end of its travel — actuator stuck open (wastegate held wide open, VGT vanes seized at maximum opening) or sensor pegged high. Boost suffers — typically underboost on VGT, overboost-protection-off on wastegate.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Turbocharger boost control position sensor A reports actuator travel to the control module, which checks whether the actuator follows its requested position. This code sets when the reading stays near the high end when it should move away, pointing to a pegged or misadjusted sensor, wiring trouble, or an actuator or linkage binding there; boost may then be too low or trigger overboost protection.
Common causes
Most likely first.
- Boost-control actuator or linkage binding near the high-travel end
- Position sensor A misadjusted or reporting incorrectly
- Damaged actuator wiring or connector
Symptoms
- Check-engine light may come on
- Reduced engine power or boost may occur
How to diagnose it
- Record freeze-frame data and compare commanded with actual sensor A position and boost pressure in live data to see when the high reading occurs.
- Inspect sensor A's connector and harness for damaged insulation, loose pins, corrosion, or a poor connection.
- Check the actuator and linkage for binding near the high-travel end, including whether the wastegate or VGT mechanism moves freely.
- Run a supported actuator command test, if available, and observe whether sensor A follows the requested movement.
- Check sensor A adjustment and circuit operation against the manufacturer's specification before condemning the actuator.
Common fixes
- Repair damaged wiring or poor connections at sensor A.
- Correct sensor A adjustment if it is outside the manufacturer's procedure.
- Free or repair a binding actuator linkage.
- Replace sensor A or the actuator only after testing identifies which one fails to track movement.
Can I keep driving?
Keep acceleration light and avoid towing until boost control is checked, since the vehicle may have reduced power or enter overboost protection. Stop if power drops sharply, smoke becomes heavy, or unusual turbo noise develops.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.