Powertrain
generic / SAE
P0AA5
Hybrid/EV Battery Negative Contactor Circuit Stuck Open
The HV battery negative contactor is stuck open. HV system cannot establish a complete circuit.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / numberA / A5
Possible causes
- Contactor mechanically failed high
- Contactor coil burnt out medium
- Carbon or debris buildup preventing free movement low
Symptoms
- EV/hybrid system warning light on
- Reduced power output or limp mode
- Charging may fail or be slowed
- Reduced electric range
Inspection / repair
- Difficulty: hard
- DIY: shop recommended
- Estimated cost: 400–2500 €
- Estimated time: 2–8 h
- Component: hv battery negative contactor
- Component: bms
- MIL / check engine light
- limp mode possible
Sources
References
sae:J2012