What it means
The battery charger control module B is not performing as expected. The code does not identify a specific internal failure.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Battery charger control module B manages charging functions and exchanges information with the battery management system. This code sets when the module's overall operation does not meet expected performance, but it does not identify a particular internal component or failure.
Common causes
Most likely first.
- Internal module fault
- Communication with BMS degraded
Symptoms
- Charge status indicator shows fault
- Charging may not start or interrupts
- Slower-than-expected charge rate
How to diagnose it
- Read freeze-frame data and all charging and battery-management codes to see whether module B's performance fault occurs with a supply, temperature, or communication problem.
- Check scan-tool data for module B charge requests, charge status, and communication with the battery management system during an affected charging session.
- Inspect the module B connectors and accessible wiring for looseness, moisture, corrosion, or damage, with the vehicle powered down as specified by the manufacturer.
- Check module B's power and ground circuits against the manufacturer's specification before judging the module itself.
- If its supplies and wiring are sound, follow the manufacturer's communication and module performance checks to distinguish a module fault from a battery-management system issue.
Common fixes
- Repair loose, corroded, or damaged module B wiring and connectors.
- Restore a faulty power or ground connection to the charger control module.
- Address a confirmed battery-management system communication fault.
- Replace battery charger control module B if its supplies, wiring, and communications pass but its performance remains out of specification.
Can I keep driving?
If charging is interrupted or the charge rate is reduced, avoid journeys that depend on the expected battery range. Stop if a high-voltage warning appears or the vehicle cannot enter Ready mode.
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.