P0AA6 on Hyundai: How to Diagnose & Fix
Hybrid Battery Voltage System Isolation Fault
1 Hyundai model · 1 documented issue · 1 critical
P0AA6 on Hyundai by model: symptoms, diagnosis and fix
NHTSA recall 22V-941 covers 853 model-year 2021 Kona EV vehicles. Insufficient sealing of the Electric Power Control Unit (EPCU) DC-DC converter housing can allow an internal coolant leak and contaminate the EPCU main controller. The contamination can trigger limited-mobility fail-safe mode or, in limited instances, cause sudden loss of motive power or a vehicle stall.
Common Symptoms
- Malfunction Indicator Lamp illumination
- Check Electric Vehicle System warning message
- Limited-mobility fail-safe mode
- Sudden loss of motive power or vehicle stall
How to Fix
Check the VIN for NHTSA recall 22V-941 (Hyundai 239). Hyundai dealers inspect the EPCU and replace it if necessary, free of charge.
Sources for this issue (1)
P0AA6 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0AA6 mean on a Hyundai?
P0AA6 stands for "Hybrid Battery Voltage System Isolation Fault." P0AA6 is a hybrid/EV code meaning the battery management system detected an isolation (insulation) fault between the high-voltage battery system and the vehicle's chassis ground. For safety, the high-voltage system is normally electrically isolated from the metal body; this code sets when the measured insulation resistance drops too low, suggesting current could leak to the chassis. This is treated as a serious safety concern and often disables hybrid/EV operation or limits propulsion. The vehicle should be inspected by a qualified hybrid technician, as high-voltage components can pose a shock hazard. On Hyundai it is documented across 1 model: Kona.
What are the most common causes of P0AA6?
The most common causes of P0AA6 are: Moisture or coolant intrusion inside the high-voltage battery pack, Damaged or chafed insulation on high-voltage cables, Corrosion or water in high-voltage connectors, Failed or leaking battery cell/module, Faulty inverter, converter, or A/C compressor (high-voltage components), Damaged high-voltage wiring rubbing against the chassis, Failed battery isolation/monitoring sensor. The specific cause varies by vehicle.
How much does it cost to fix P0AA6 on a Hyundai?
Repair costs vary widely with the root cause and Hyundai model; each issue on this page carries its own estimate where one is published.
Looking for P0AA6 on a different make?
View P0AA6 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.