Hybrid/EV Battery Cell Voltage Imbalance
2012-2017 Buick Regal 2.4L I4 Hybrid
Description
One or more cells in the HV battery pack have significantly different voltage levels from the rest. Cell imbalance reduces pack capacity and can indicate cell failure.
Symptoms
- Hybrid/EV warning light
- Reduced electric range
- Battery SOC drops rapidly
- Inconsistent regenerative braking
- Power output limited
- Uneven charging behavior
Common Causes
- Individual cell degradation
- Cell internal resistance increase
- Temperature variation across pack
- BMS balancing circuit failure
- Manufacturing defect in cell
Diagnostic Steps
- Read individual cell voltages via scan tool
- Identify weakest cell or module
- Check cell temperatures across pack
- Test cell internal resistance
- Review BMS balancing history
Repair Notes
Replace failed battery module(s). In some vehicles, individual modules can be replaced. Full pack replacement if multiple modules affected.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P3201 on Other Vehicles
Common Questions
What does code P3201 mean on a 2012-2017 Buick Regal?
P3201 stands for "Hybrid/EV Battery Cell Voltage Imbalance". One or more cells in the HV battery pack have significantly different voltage levels from the rest. Cell imbalance reduces pack capacity and can indicate cell failure.
What are the symptoms of P3201 on a Buick Regal?
Common symptoms of P3201 include: Hybrid/EV warning light, Reduced electric range, Battery SOC drops rapidly, Inconsistent regenerative braking, Power output limited, Uneven charging behavior.
What causes P3201 on a 2012-2017 Buick Regal?
Common causes of P3201 include: Individual cell degradation, Cell internal resistance increase, Temperature variation across pack, BMS balancing circuit failure, Manufacturing defect in cell.