P0AA6
Hybrid Battery Voltage System Isolation Fault
The BMS isolation monitor detects insulation resistance between HV positive/negative bus and chassis ground below the safe threshold, indicating insulation failure somewhere in the HV system.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: shop_only
Common causes
Ordered by how often each turns out to be the cause.
- HV cable insulation damagedCommon
- Moisture intrusion in HV componentPossible
- Aged HV component insulationLess likely
Parts involved
- Hv Battery
- Hv Cabling
- Inverter
- Charger
P0AA6 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.