OBD-II code · Powertrain (generic)
P0A77 Generator Phase W Current High
Phase W current of the generator exceeds the expected window. Indicates phase short or stalled rotor.
Is it safe to drive with P0A77?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyShort between motor phases
- PossibleRotor stalled - high stall current
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 3–16 h
- Emissions test
- Usually unaffected
- Parts involved
- Generator Phase W, Inverter
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.