What it means
The cell balancing circuit G 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 circuit G lets the BMS trim charge differences in its assigned cell group. The BMS monitors whether the G switching path activates when commanded; this code sets when the path remains inactive, consistent with an open switch, open circuit, or failed BMS driver.
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
- Record freeze-frame data and live cell-group voltages, temperatures, and G-channel balancing status to confirm whether balancing was requested.
- Compare the G group’s voltage with other groups and check whether temperature or charge conditions would inhibit balancing.
- With the high-voltage system made safe using the vehicle’s service procedure, inspect G-channel connectors and wiring for looseness, corrosion, or damage.
- Test the G balancing path for an open circuit using the manufacturer’s procedure and specification.
- If the circuit and switching component pass, evaluate the BMS driver output for circuit G.
Common fixes
- Secure or clean a poor G-channel connector.
- Repair open or damaged wiring in the G-channel harness.
- Replace a failed G balancing switch or component.
- Repair or replace the BMS if its G-channel driver is faulty.
Can I keep driving?
Expect possible reduced power, charging limits, or shorter electric range, and avoid long trips until the fault is diagnosed. Stop if the vehicle enters limp mode or displays a battery warning; high-voltage repairs require the vehicle’s safety procedure.
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.