What it means
The cell thickness sensor signal for hybrid/EV battery pack B does not meet the system’s plausibility checks. The code does not by itself establish whether the cause is the sensor, its circuit, or the measured cell condition.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The BMS checks whether the cell thickness sensor signal in hybrid/EV battery pack B is plausible as conditions change. This code sets when the reading fails those checks, which can happen if the sensor is offset or failed, its mounting has shifted, or its wiring is faulty.
Common causes
Most likely first.
- Sensor offset or failure
- Sensor mounting displaced
- Wiring or connector 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
- Record freeze-frame data and graph pack B thickness sensor live data to see whether it changes plausibly with operating conditions.
- Compare pack B readings with other available cell measurements and check for related BMS codes that could indicate a cell condition.
- With the vehicle made safe under the manufacturer's procedure, inspect the pack B sensor mounting, harness, and connector for movement, damage, moisture, or corrosion.
- Check the pack B sensor circuit for intermittent opens or poor contact while monitoring the signal, following the manufacturer's procedure.
- Test sensor response and mounting position against the manufacturer's specifications before attributing the fault to BMS calibration.
Common fixes
- Secure the pack B thickness sensor if its mounting has shifted and the manufacturer's procedure permits adjustment.
- Repair loose, damaged, or corroded pack B sensor wiring and connectors.
- Replace the pack B thickness sensor if its output remains implausible.
- Perform manufacturer-specified BMS calibration after confirming the sensor and circuit are sound.
Can I keep driving?
The BMS may restrict power or charging while pack B thickness readings are implausible. Limit driving and avoid heavy loads until the cause is checked, especially if the warning is accompanied by heat, a sudden power reduction, or an abnormal pack appearance.
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.