What it means
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.
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 B reports actuator travel so the control module can compare it with the requested position. This code sets when sensor B stays near the high end when it should move away, suggesting a pegged or misadjusted sensor, wiring trouble, or a B-side actuator or linkage binding there; it does not by itself confirm a second turbo.
Common causes
Most likely first.
- Boost-control actuator or linkage binding near the high-travel end
- Position sensor B 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
- Save freeze-frame data and compare commanded and actual sensor B position with boost pressure in live data to identify when the high reading occurs.
- Inspect sensor B's connector and harness for loose or corroded terminals, damaged insulation, or poor contact.
- Check the B-side actuator and linkage for binding at the high-travel end and inspect the associated wastegate or VGT mechanism.
- Run a supported actuator command test, if available, and watch whether sensor B tracks the requested movement.
- Check sensor B adjustment and circuit operation against the manufacturer's specification to separate a feedback fault from mechanical binding.
Common fixes
- Repair damaged wiring or poor connections at sensor B.
- Correct sensor B adjustment using the manufacturer's procedure.
- Free or repair a binding B-side linkage or actuator.
- Replace sensor B or the actuator if testing confirms it cannot track the commanded position.
Can I keep driving?
Use light throttle and avoid towing while the B-side boost control is unreliable; power may be reduced or boost protection may intervene. Stop if power falls 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.