OBD-II code · Powertrain (generic)
P0AA5 Hybrid/EV Battery Negative Contactor Circuit Stuck Open
The HV battery negative contactor is stuck open. HV system cannot establish a complete circuit.
Is it safe to drive with P0AA5?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyContactor mechanically failed
- PossibleContactor coil burnt out
- Less likelyCarbon or debris buildup preventing free movement
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
- 2–8 h
- Emissions test
- Usually unaffected
- Parts involved
- Hv Battery Negative Contactor, Bms
Related codes
- P0AA2Hybrid/EV Battery Positive Contactor Circuit Stuck Open
- P0AA3Hybrid/EV Battery Negative Contactor Circuit
- P0AA4Hybrid Battery Negative Contactor Circuit
- P0AA6Hybrid Battery Voltage System Isolation Fault
- P0AA7Hybrid/EV Battery Voltage Isolation Sensor Circuit
- P0AA8Hybrid/EV Battery Voltage Isolation Sensor Circuit Range/Performance
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.