What it means
The system detects an abnormal thickness measurement for a cell in hybrid/EV battery pack B. The code alone does not establish whether the cause is cell deformation, a sensor fault, or a wiring or measurement problem.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The BMS monitors a thickness measurement for a cell in hybrid/EV battery pack B. This code sets when the reported thickness is abnormal; it does not establish whether the cell is deformed or the sensor and measurement system are at fault.
Common causes
Most likely first.
- Cell thickness sensor or wiring fault
- Cell deformation or swelling
- BMS measurement or calibration fault
Symptoms
- EV/hybrid system warning light on
- Reduced power output or limp mode
- Charging may fail or be slowed
- Reduced electric range
How to diagnose it
- Use a scan tool to record freeze-frame data and compare pack B thickness readings with other available cell measurements to locate an outlier.
- Check for related BMS or battery temperature and voltage codes that could help distinguish a cell condition from a measurement problem.
- With the vehicle powered down according to the manufacturer's safety procedure, inspect pack B sensor wiring and connectors for damage, moisture, looseness, or corrosion.
- Have the pack B cell and thickness sensor inspected for swelling, deformation, displacement, or damage using the manufacturer's service procedure.
- Test the pack B thickness sensor circuit and compare its readings with the manufacturer's specifications before considering BMS calibration or module faults.
Common fixes
- Repair damaged, loose, or corroded pack B thickness sensor wiring or connectors.
- Correct a displaced pack B thickness sensor mounting if permitted by the manufacturer's procedure.
- Replace a failed pack B cell thickness sensor.
- Service or replace a deformed pack B cell and perform any required BMS calibration.
Can I keep driving?
The BMS may limit power or charging when pack B thickness is abnormal, so avoid long trips and hard acceleration, and do not continue charging if a battery fault is reported. If the pack appears swollen, unusually hot, or emits an odor, stop using the vehicle and arrange battery service.
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.