What it means
The cell balancing circuit K reports a range/performance condition. Cell-group voltage equalization may be impaired on this channel.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Balancing circuit K controls equalization for the battery cell group assigned to channel K. The battery management system checks whether that channel’s response stays within the expected range when balancing is commanded. This code sets when the K circuit responds, but its performance or the associated cell-group readings fall outside the expected range.
Common causes
Most likely first.
- Balancing circuit or wiring fault
- BMS driver fault
- Cell-voltage or temperature condition affecting balancing
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 review live K-channel commands, cell-group voltages, and relevant temperature readings to identify the conditions that triggered the fault.
- Compare the K group’s voltage and temperature trends with neighbouring groups during charging or other conditions when balancing is allowed.
- Inspect the K balancing circuit connector and wiring for corrosion, loose terminals, chafing, or damage that could cause an inconsistent response.
- Test the K balancing circuit and driver wiring against the manufacturer's procedure and specification, checking for intermittent faults as well as opens or shorts.
- If wiring checks pass, have the K balancing component and battery management system driver evaluated alongside the cell-voltage and temperature data.
Common fixes
- Repair a loose, corroded, or damaged K-channel connection or wire.
- Replace a faulty K-channel balancing component if circuit testing confirms it.
- Repair or replace a failed battery management system driver.
- Address a confirmed cell-voltage or temperature problem that is preventing normal K-channel balancing.
Can I keep driving?
The vehicle may limit power or charging, so keep trips short and avoid relying on full electric range until the fault is diagnosed. If reduced power, a charging failure, or limp mode occurs, stop safely and arrange service; continued use may worsen cell-group imbalance.
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.