Code Definition

P0AA2 — Hybrid battery positive contactor circuit stuck open

System: Powertrain  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About P0AA2

P0AA2 is a generic (obd-ii standard) powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P0AA2 is stored, the module has detected an open (broken or disconnected) electrical path in the monitored circuit.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

Because P0AA2 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

This DTC is set when the hybrid/EV control module commands the hybrid battery positive contactor to close, but the circuit remains open. The system monitors voltage and current on the high-voltage output side of the contactor. If no voltage is detected when the contactor is expected to be closed, the module interprets this as the contactor being stuck open.

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