What are the common causes of P0A0A?

A faulty high voltage interlock switch A. An open in the high voltage interlock A wiring. Corrosion in a high voltage connector. A loose high voltage service disconnect. A fault in the powertrain control module.

Inspect the high voltage interlock A wiring and connectors. Check the high voltage service disconnect seating. Test interlock A continuity with the correct equipment. Verify powertrain control module power and ground. Clear the code and retest.

P0A0A

High Voltage System Interlock Circuit A

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

What it means

P0A0A means High Voltage System Interlock Circuit A.

Check these first

A faulty high voltage interlock switch A
An open in the high voltage interlock A wiring
Corrosion in a high voltage connector
A loose high voltage service disconnect
A fault in the powertrain control module

What to do next

Inspect the high voltage interlock A wiring and connectors
Check the high voltage service disconnect seating
Test interlock A continuity with the correct equipment
Verify powertrain control module power and ground
Clear the code and retest

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Updated

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