What it means
The battery charger B cooling system does not maintain target temperatures under load. Coolant flow reduced, fan failure, or radiator fouling.
At a glance
- Usually lights the check-engine light
How it works
Battery charger B uses a cooling circuit to carry heat away while charging, and the control module monitors whether that circuit can keep temperatures near the commanded target under load. This code sets when charger B's cooling performance falls short, which can happen if coolant flow is restricted or its cooling fan does not operate correctly.
Common causes
Most likely first.
- Coolant flow reduced
- Cooling fan failure
Symptoms
- Charge status indicator shows fault
- Charging may not start or interrupts
- Slower-than-expected charge rate
How to diagnose it
- Review freeze-frame data and charger B temperature and cooling-command live data to see when the temperature began rising and whether the fault occurs under load.
- With the vehicle off and cool, check the specified coolant level and look for leaks, kinked hoses, or obvious restrictions in charger B's cooling circuit.
- Inspect the cooling fan and its wiring for damage or loose connections, then check with a scan tool whether the fan responds to a commanded test if available.
- Check for radiator or heat-exchanger blockage and confirm coolant can circulate through the charger B circuit.
- If the cause is not apparent, compare temperature-sensor readings and cooling-system operation with the manufacturer's diagnostic procedure.
Common fixes
- Restore the coolant level and repair any leak using the specified coolant.
- Clear debris from the charger B heat exchanger or radiator.
- Repair damaged fan wiring or a loose fan connector.
- Replace a failed cooling fan or repair the restricted coolant-flow component.
Can I keep driving?
Charging may slow, stop, or be unavailable, and continued charging with inadequate cooling can cause the charger to overheat or shut down. Avoid relying on fast or unattended charging until the cooling fault is resolved.
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.