What it means
The control module detected hybrid/EV battery discharging voltage above its calibrated limit. The cause and vehicle response depend on the vehicle.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The hybrid or EV battery management system monitors pack voltage while the battery supplies energy to the vehicle. This code sets when voltage during discharge exceeds the calibrated limit; a high state of charge, regenerative energy behavior, or an abnormal cell group may contribute depending on the vehicle.
Common causes
Most likely first.
- State of charge near full
- Regen braking overshoot
- Pack cell imbalance approaching service threshold
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 note whether the event occurred during acceleration, coasting, regenerative braking, or a high state-of-charge condition.
- Use a scan tool to review battery discharge voltage, state of charge, power demand, and any related battery or inverter codes.
- Compare cell-group voltage data for an imbalance that could make pack voltage readings abnormal.
- Inspect accessible battery and inverter connections for looseness, corrosion, or damage, following the vehicle's high-voltage precautions.
- Check battery voltage sensing and discharge control using the service procedure, comparing readings with the manufacturer's specification.
Common fixes
- Correct an abnormal operating or load condition if scan data shows it coincided with the event.
- Repair a damaged or poorly connected accessible battery or inverter connection.
- Repair a confirmed battery voltage sensing fault.
- Service a cell-group imbalance or battery fault only after testing confirms it.
Can I keep driving?
Avoid hard acceleration and steep or prolonged regenerative braking if the hybrid warning or reduced-power mode is active. Stop safely if propulsion becomes unpredictable, since continued use may trigger further power limitation or shutdown.
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.