What are the common causes of P0AA2?

A positive contactor that has failed open. No coil signal reaching the positive contactor. An open in the positive contactor wiring. A failing hybrid control module that will not close the contactor. A high voltage battery fault blocking contactor closing.

Check the positive contactor for coil power and ground. Measure resistance across the positive contactor. Inspect the positive contactor wiring for an open. Scan for other hybrid codes that block closing and check high voltage battery condition. Replace the positive contactor if it stays open. Clear the code and retest.

P0AA2

Hybrid/EV Battery Positive Contactor Circuit Stuck Open

System: Powertrain control (P code)
Lamp: Check Engine Light
Category: Powertrain - Hybrid Propulsion

What it means

P0AA2 means Hybrid/EV Battery Positive Contactor Circuit Stuck Open.

Check these first

A positive contactor that has failed open
No coil signal reaching the positive contactor
An open in the positive contactor wiring
A failing hybrid control module that will not close the contactor
A high voltage battery fault blocking contactor closing

What to do next

Check the positive contactor for coil power and ground
Measure resistance across the positive contactor
Inspect the positive contactor wiring for an open
Scan for other hybrid codes that block closing and check high voltage battery condition
Replace the positive contactor if it stays open
Clear the code and retest

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Updated

Generic SAE J2012 definition. Last updated 2026-10-10.