What it means
The coupler B temperature exceeds the safety threshold during charging. The on-board charger negotiates voltage, current and safety with the EVSE; a fault interrupts charging or limits it to AC slow-charge despite a DC fast charger being attached.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The charging system monitors temperature at coupler B while the vehicle charges. This code sets when that coupler temperature exceeds its safety threshold, so charging may be stopped or limited to protect the connector.
Common causes
Most likely first.
- Coupler contacts oxidised
- Charging current above coupler rating
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 charging history to see whether the fault occurs at high charging current or after a particular charge duration.
- With charging stopped, inspect coupler B and its mating inlet for oxidation, discoloration, heat damage, or debris.
- Check that the coupler is fully seated and that its contacts are clean and undamaged; do not touch or probe high-voltage contacts.
- Compare the requested charging current and coupler rating with the vehicle and charging equipment specifications.
- If the contacts and charging rate appear appropriate, have the coupler temperature reading and its sensing circuit checked using the manufacturer's procedure.
Common fixes
- Clean accessible coupler contacts using an approved method.
- Replace a coupler with damaged or oxidized contacts.
- Use charging equipment and current within the coupler's rated limits.
- Repair or replace a faulty coupler temperature sensor or its wiring if testing confirms a fault.
Can I keep driving?
Stop charging if the coupler becomes unusually hot, shows damage, or repeatedly interrupts charging. Do not force continued charging; overheating can damage the connector or inlet.
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.