OBD CodesWhat it means
Hybrid cars have a high-voltage battery, an inverter that drives the electric motor, and a converter that charges the ordinary 12 volt battery. These codes report that the battery has weakened, that high voltage is leaking to the car body, or that the electronics or their cooling are not working properly.
Codes in this group
| Code | Meaning |
|---|---|
| P0A0F | Engine failed to start |
| P0A7F | Hybrid battery pack has deteriorated |
| P0A80 | Hybrid battery pack needs replacement |
| P0A93 | Inverter cooling system not performing as expected |
| P0A94 | DC to DC converter not performing as expected |
| P0AA6 | Hybrid battery voltage isolation fault |
Bank 1 is the side of the engine that has cylinder 1. Sensor 1 is before the catalytic converter and sensor 2 is after it. More terms explained.
What you may notice
- Hybrid system warning or "check hybrid system" message
- Petrol engine running more than usual
- Lower fuel economy
- Reduced power, or the car refusing to go into Ready mode
Common causes
Most likely first:
- An aged high-voltage battery with weak cells
- A blocked battery cooling fan or vent, often by dust or pet hair
- A failed inverter coolant pump or low inverter coolant
- Moisture or damage causing a high-voltage leak
- A weak 12 volt battery
What to check first
- Check the battery cooling vent in the cabin is not covered or clogged
- Have the 12 volt battery tested
- Never open orange high-voltage cables or covers: the voltage can kill. Use a workshop trained on hybrids
Have a mechanic confirm. A fault code tells you which system reported a problem, not which part has failed. The same code can have several causes, and they differ between car models. Use this page to understand the code, then have a qualified mechanic test the car before any part is replaced.
After the repair
Once the cause is fixed, the code can be cleared with a scan tool, or the warning light goes out by itself after several trips without the fault. Clearing a code without fixing the cause only hides it for a while. More about clearing codes.
Related codes
. All codes.
Written in November 2026. These are generic OBD-II codes, the same on all makes. Causes and repair steps differ between models.