What it means
Turbocharger B Boost Control Position At High Limit: the control module has detected this fault condition. This affects turbo/supercharger boost-pressure control.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The boost control actuator moves a turbocharger wastegate or another boost-control mechanism, while its position sensor reports how far it has moved. The control module compares the reported position with the requested position; this code sets when Turbocharger B's reported position reaches or exceeds its high limit.
Common causes
Most likely first.
- Wastegate or boost-control actuator stuck closed
- Binding actuator linkage
- Position sensor or calibration fault
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 and reported Turbocharger B boost-control positions to see when the position reaches its limit.
- With the engine off, inspect Turbocharger B's actuator, linkage, connector, and wiring for damage, disconnection, or signs of binding.
- Check whether the actuator linkage moves freely through its intended range without forcing it.
- Use a scan tool's supported actuator test to compare commanded movement with the position sensor response.
- Test the position sensor circuit and actuator wiring for opens, shorts, and poor connections, then check the actuator and calibration against the manufacturer's specification.
Common fixes
- Repair damaged or loose Turbocharger B actuator wiring or connector terminals.
- Free or repair binding Turbocharger B actuator linkage.
- Replace a failed Turbocharger B position sensor or actuator assembly.
- Carry out the applicable actuator calibration or relearn.
Can I keep driving?
Drive gently and avoid hard acceleration, towing, or other high-load use because boost may be limited or poorly controlled. Stop if power drops sharply or the engine shows signs of overheating.
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.