What it means
The boost control module B reports that its calibration data is not present or not learned. Boost regulation falls back to default values until programming or adaptation completes.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
- The engine or gearbox may go into limp mode
How it works
Boost control module B manages its assigned turbocharger or supercharger boost functions using stored calibration and learned settings. This code sets when module B's calibration is missing or not learned, so the module may fall back to default control and limit performance.
Common causes
Most likely first.
- Module replaced without programming
- Calibration memory corrupted after voltage drop
Symptoms
- Charge status indicator shows fault
- Charging may not start or interrupts
- Slower-than-expected charge rate
How to diagnose it
- Record freeze-frame data and scan related modules for low-voltage, communication, or calibration codes that may have occurred at the same time.
- Review service history for replacement of boost control module B or a recent battery discharge or voltage drop.
- Inspect module B's connectors, power, and grounds for looseness, corrosion, or damage that could interrupt communication or memory.
- Use a compatible scan tool to confirm module B's calibration status and check that its software identification matches the vehicle.
- If calibration is missing, carry out the manufacturer's programming or adaptation procedure and confirm the fault stays cleared.
Common fixes
- Correct unstable battery voltage or repair a faulty power or ground connection to module B.
- Program or relearn boost control module B using the manufacturer's procedure.
- Replace module B only if it fails to retain calibration after programming and circuit checks.
Can I keep driving?
Reduced power can make merging, overtaking, or climbing hills unsafe, so drive gently and avoid demanding loads until module B is calibrated. Stop and arrange service if the vehicle cannot maintain a safe speed or shows additional charging or power faults.
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.