OBD-II code · Powertrain (generic)
P0A78 Drive Motor A Inverter Performance
The drive motor A inverter does not deliver commanded torque within tolerance under load, indicating thermal limit or partial IGBT failure.
Is it safe to drive with P0A78?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyThermal derating active
- PossiblePartial IGBT failure
Symptoms
- EV/hybrid system warning light on
- Reduced motor power or torque
- Possible limp mode or vehicle shutdown
Repair at a glance
- Difficulty
- Shop_only
- DIY friendly
- Best left to a mechanic
- Typical labour
- 4–16 h
- Emissions test
- Usually unaffected
- Parts involved
- Inverter, Drive Motor A
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.