P0AAE Hybrid/EV Battery Negative Contactor Circuit

P0AAE indicates a hybrid or EV battery negative contactor circuit problem. The negative-side high-voltage contactor cannot be commanded or monitored correctly.

Code status

Needs verification

Not yet verified against SAE J2012_202509 / J2012DA. Treat unverified rows as a lookup aid, not repair authority.

System: Hybrid / EV
Scope: iso-sae-controlled-p0
Standard: SAE J2012 / ISO 15031-6
Source: legacy-import

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not bypass the negative contactor or force the vehicle ready with an unresolved contactor circuit fault.

Useful checks before replacing parts

Check negative contactor command, feedback, pack voltage, load-side voltage, precharge status, 12-volt supply, freeze-frame data, and contactor codes.
Inspect negative contactor control wiring, battery ECU connectors, fuses, grounds, service disconnect status, corrosion, water intrusion, and connector seating.
Verify contactor state changes during ready-up and shutdown using service data before replacing high-voltage battery parts.

Related OBD-II codes

These nearby hybrid / ev entries can help compare wording and fault area. They may share the same verification status as the source database.