P0AA6 on GMC: How to Diagnose & Fix
Hybrid Battery Voltage System Isolation Fault
1 GMC model · 1 documented issue
P0AA6 on GMC by model: symptoms, diagnosis and fix
DC fast charging sessions terminate prematurely or fail to initiate at certain charger networks. Communication errors between the vehicle and charger can prevent charging above 80% or cause sessions to stop repeatedly.
Common Symptoms
- Charging session stops unexpectedly
- Unable to initiate DC fast charge
- Charging speed drops to zero
- Error message on charger screen
How to Fix
Ensure vehicle software is updated. Try different CCS charger brands if one consistently fails. Precondition the battery before DC fast charging by using the "Target Charger" feature in navigation. Dealer can update the charge port module firmware.
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 GMC?
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 GMC it is documented across 1 model: Hummer EV SUV.
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 GMC?
Repair costs vary widely with the root cause and GMC 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.