OBD
P0AA3
Hybrid/EV Battery Negative Contactor Circuit
What it means
P0AA3 means Hybrid/EV Battery Negative Contactor Circuit.
Check these first
- Corrosion or damage at the negative contactor
- A worn negative contactor
- High resistance in the contactor circuit
- A failed battery management system
What to do next
- Read negative contactor state on a scan tool
- Inspect the contactor and connections for corrosion
- Measure resistance in the contactor circuit
- Test the battery management system
- Replace the contactor if it is worn
- Clear the code and retest
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Updated
Generic SAE J2012 definition. Last updated 2026-10-10.