P2D38
Hybrid/EV Battery Pack Heater Performance
The HV battery pack heater does not raise battery temperature within the calibrated time window. Heater element aged or supply current insufficient.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
Symptoms
- EV/hybrid system warning light on
- Reduced power output or limp mode
- Charging may fail or be slowed
- Reduced electric range
Common causes
Ordered by how often each turns out to be the cause.
- Heater element aged - low outputCommon
- Supply current insufficientPossible
- Pack cell imbalance approaching service thresholdLess likely
Parts involved
- Hybrid Battery Heater
- Battery Pack Thermal Loop
P2D38 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.