What it means
The cell balancing circuit N reports a stuck off 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 channel N lets the battery management system reduce charge differences in its monitored cell group. This code sets when channel N fails to turn on when commanded, so that group may not receive balancing when needed.
Common causes
Most likely first.
- Open balancing switch or circuit
- Open or damaged balancing-circuit wiring
- BMS driver 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
- Save freeze-frame data and BMS codes, then compare channel N's commanded and reported states with its cell-group voltage relative to neighboring groups.
- With the vehicle safely powered down per its service instructions, inspect channel N connectors and wiring for breaks, backed-out pins, corrosion, or other damage.
- Test channel N wiring for continuity and shorts using the manufacturer's procedure and specified limits.
- When the system commands balancing, check whether channel N's signal or response changes as expected under the manufacturer's test procedure.
- If the wiring is sound, test the channel N balancing switch and BMS driver for an open or failed output.
Common fixes
- Reconnect or repair an open, damaged, or corroded channel N wire or connector.
- Replace a failed or open channel N balancing switch.
- Repair or replace the BMS driver if its channel N output fails the specified test.
- Confirm channel N responds to commands and recheck cell-group balance.
Can I keep driving?
The vehicle may limit power or charging, so keep trips short and stop if a battery warning or severe power reduction occurs. Continued use without channel N balancing can allow the affected cell group to drift from the rest of the pack.
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.