OBD-II code · Powertrain (generic)
P0AA7 Hybrid/EV Battery Voltage Isolation Sensor Circuit
The ECM detects a circuit fault on the hybrid/ev battery voltage isolation sensor circuit. Reading cannot be used reliably for control.
Is it safe to drive with P0AA7?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelySensor failed
- PossibleWiring or connector fault
- Less likelyPack 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
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 2–7 h
- Emissions test
- Usually unaffected
- Parts involved
- Hv Battery Voltage Isolation Sensor, Wiring Harness, Bms
Related codes
- P0AA4Hybrid Battery Negative Contactor Circuit
- P0AA5Hybrid/EV Battery Negative Contactor Circuit Stuck Open
- P0AA6Hybrid Battery Voltage System Isolation Fault
- P0AA8Hybrid/EV Battery Voltage Isolation Sensor Circuit Range/Performance
- P0AA9Hybrid/EV Battery Voltage Isolation Sensor Circuit Low
- P0AAAHybrid/EV Battery Voltage Isolation Sensor Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.