What it means
The cell balancing circuit A 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
The battery management system uses circuit A to switch balancing components that trim voltage differences among the cell groups assigned to that channel. It sets P0DAE when it commands balancing on circuit A but detects that the circuit remains inactive, so those groups may not be equalized as intended.
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
- Record freeze-frame data and battery-management codes, then compare circuit A status with the other balancing channels to see when the fault occurs.
- With the vehicle powered down according to the manufacturer's procedure, inspect accessible circuit A connectors and harnesses for looseness, damage, corrosion, or signs of moisture.
- Use scan-tool data to compare the voltages of cell groups associated with circuit A before and after a commanded balancing event, if the vehicle supports that test.
- Have a qualified technician test circuit A wiring continuity and connections against the manufacturer's specification, since an open path can prevent balancing.
- If the wiring checks out, have the battery management system and pack tested for an internal balancing-switch or control fault.
Common fixes
- Repair a loose, damaged, or corroded circuit A connector or harness.
- Repair an open circuit A connection found during wiring tests.
- Correct a battery-management ground or connection fault if testing identifies one.
- Repair or replace the failed circuit A balancing component or battery-management module as confirmed by pack-level diagnosis.
Can I keep driving?
Avoid long trips, heavy acceleration, and relying on the vehicle for a journey where reduced power or charging failure would be hazardous. If a hybrid/EV warning, limp mode, unusual heat, or a battery fault message appears, stop in a safe place and follow the vehicle's instructions; do not open or probe 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.