P0AA6 Code: Hybrid Battery Voltage Isolation — Causes & Fix
P0AA6 means the hybrid/EV system detected a loss of isolation between the high-voltage battery and the chassis — a potential high-voltage safety fault.
- Applies to
- All OBD-II vehicles (any make or model)
- Est. repair cost
- $200 – $3,000
- Time to fix
- 1–4 hours
What it means
Causes include coolant/moisture intrusion, damaged HV cabling/insulation, or a failing HV component. P0AA6 is a generic OBD-II code defined in the SAE J2012 standard, so it applies to virtually any 1996-or-newer OBD-II vehicle regardless of make. Fix the underlying fault, then clear the code with an OBD-II scan tool — it will return if the problem isn't resolved.
Symptoms
- Check engine + hybrid/red warning
- Reduced power or no ready mode
- Safety warning messages
How to fix it
- 1
Stop driving and get it inspected
1. This is a high-voltage safety fault — do not attempt DIY high-voltage work.
- 2
Have a hybrid tech isolate it
1. A qualified hybrid technician locates the isolation loss (often coolant leaks or damaged HV cable) and repairs it, then clears the code.
Frequently asked questions
Is P0AA6 dangerous?
It can be — it indicates a loss of high-voltage isolation. Have it inspected by a qualified hybrid/EV technician; do not poke around the orange (HV) cables yourself.
Last updated July 19, 2026
Guidance only — always consult a qualified professional or the official service manual before carrying out repairs.