P2C87
Hybrid/EV Battery Voltage External Isolation Warning
The hybrid control module detects an early-warning external isolation degradation. Pre-failure indicator for HV cable insulation against chassis.
- 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.
- Moisture in HV connectorCommon
- HV cable insulation agedPossible
- Pack cell imbalance approaching service thresholdLess likely
Parts involved
- Hv Battery
- Hv Wiring
- Isolation Monitor
P2C87 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.