OBD-II · Engine and powertrain (P)
P0A7F
Hybrid/EV battery pack deterioration
What it means
The system has found that the high-voltage battery has lost too much capacity or its internal resistance has risen too far.
Symptoms
- Hybrid/EV warning light
- Reduced electric range or power
- Engine runs more often on hybrids
Likely causes, most likely first
| No. | Cause |
|---|---|
| 01 | normal ageing of the high-voltage battery |
| 02 | battery repeatedly overheated (blocked cooling fan or intake, or a faulty cooling system) |
| 03 | one or more weak cell modules |
| 04 | voltage sensing or battery control fault (less common) |
What to check, step by step
- 01Read battery state-of-health and block voltages with a scan tool
- 02Check the battery cooling fan, intake and filter or coolant circuit
- 03Have a high-voltage qualified technician inspect the pack
- 04Check for a manufacturer warranty on the high-voltage battery (often 8 years)