What it means
The cell balancing circuit C 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
Circuit C balances the cell groups assigned to that channel under battery-management control. P0DB6 sets when balancing is requested on C but the system detects no expected circuit activity, so those groups may not receive the intended voltage equalization.
Common causes
Most likely first.
- Balancing switch or circuit open
- Battery pack or BMS internal fault
- 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
- Capture freeze-frame data and battery-management codes, checking whether circuit C was commanded on but reported inactive.
- Compare voltage trends for C's assigned cell groups with other groups during charging or a supported balancing check.
- With the vehicle powered down using the manufacturer's procedure, inspect accessible circuit C wiring and connectors for an open, loose terminal, corrosion, or damage.
- Have a qualified technician test circuit C continuity and connections against the manufacturer's specification to check for an open path.
- If wiring tests pass, have the battery management system and pack checked for a failed circuit C balancing switch or internal fault.
Common fixes
- Reconnect or repair a loose or damaged circuit C connector.
- Repair an open wire or terminal in the circuit C path found during testing.
- Replace a circuit C balancing switch confirmed to be inactive.
- Repair or replace an internal battery-management or pack component when diagnosis confirms the failure.
Can I keep driving?
Restrict use to necessary shorter trips and avoid heavy loads, because the vehicle may limit power or charging and electric range can fall. If limp mode or a serious battery warning appears, stop safely and follow the vehicle's instructions; do not access the high-voltage battery.
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.