P2D9E
High Voltage System Voltage Low
The high-voltage system voltage is below the expected window. HV battery output drops, isolation event, or loaded too heavily.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
Common causes
Ordered by how often each turns out to be the cause.
- HV battery cells agedCommon
- BMS regulation outside calibrationPossible
Parts involved
- Hv Battery
- Bms
- Hv Bus
P2D9E 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.