P0AA6: Hybrid Battery Voltage System Isolation Fault
Severity: high
What it means: The hybrid system found that insulation between the high-voltage circuit and the car body has dropped, meaning high voltage may be leaking to the chassis somewhere.
Safe to drive? No. Toyota's manuals say the car may not start again until the code is cleared with a scan tool. It can usually finish the current trip, but treat it as a high-voltage safety fault.
Common symptoms
- Master warning and check hybrid system message
- Car may not restart or enter READY
- Check-engine light may stay off on some models
Likely causes, ranked
- Corroded or water-damaged high-voltage connector or cableShop
- Electric A/C compressor insulation faultShop
- Motor-generator or rear motor winding faultShop
- Hybrid battery, relay or inverter insulation faultShop
Vehicle-specific notes
- :
What it means: The hybrid system found that insulation between the high-voltage circuit and the car body has dropped, meaning high voltage may be leaking to the chassis somewhere.
Severity: High. Safe to drive? No. Toyota's manuals say the car may not start again until the code is cleared with a scan tool. It can usually finish the current trip, but treat it as a high-voltage safety fault.
DIY or shop?
Shop only. Testing needs a 500 V insulation tester and high-voltage safety gear. The detail (INF) code points to the area.
Vehicle notes
- 2019–2022 RAV4 Hybrid: owners report corrosion at the rear motor high-voltage connector. Toyota has a bulletin for it.
Before you replace parts
- Read all stored codes, including detail (INF) codes on Toyota hybrids.
- Check your VIN for recalls, service bulletins and extended coverage.
- Clear the code only after a repair, then confirm it stays off.
Safety / mechanic note
Verify with a mechanic. Hybrid systems carry dangerous high voltage. A code points to a circuit or system, not always a specific part.