What it means
During cold start, the HV battery cannot deliver the expected power. Cold cell impedance reduces available current.
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 estimates how much current the pack can supply during a cold start, using battery temperature and cell data. P2D3E sets when the pack's available power falls below the expected level in cold conditions, which can happen when cold cells have high impedance, the heater has not warmed them yet, or the cells are imbalanced.
Common causes
Most likely first.
- Cell impedance high at cold
- Battery heater not yet effective
- 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
- Use a scan tool to record freeze-frame data and compare battery temperature, available power, cell voltages, and state of charge with the reported reduced-power condition.
- Check whether the fault occurs only after a cold soak and whether battery output improves as the pack warms.
- Inspect the battery heater's accessible wiring, connectors, and coolant or air path for damage or blockage, following the vehicle's high-voltage safety procedures.
- Use scan-tool data to compare cell voltages and temperature readings across the pack for imbalance or an unusually cold section.
- Test the battery heater and its control circuit against the manufacturer's specification, then investigate pack condition if cold power remains low.
Common fixes
- Clear debris or restrictions from the battery thermal-management air or coolant path.
- Repair damaged or loose battery-heater wiring or connections.
- Repair or replace a failed battery heater or its control component.
- Have the battery pack assessed and service the imbalanced or degraded cells according to the manufacturer's procedure.
Can I keep driving?
Drive only as needed if the vehicle remains controllable, and avoid hard acceleration, steep climbs, and demanding loads because power may be limited further. Stop safely if the vehicle warns of a high-voltage battery fault or cannot maintain traffic speed.
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.