P0A1AGenerator Control Module
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0A1A reports a fault of the electronics that control the generator, either inside a hybrid inverter or in a belt starter-generator. Toyota lists P0A1A for the 2010-2015 Prius and 2012-2017 Prius V together with P0A94, P324E and P3004 as a malfunction inside the inverter assembly with converter; the repair can mean replacing the MG ECU, IPM transistors or the whole inverter. Audi stores P0A1A00 in the engine control unit of 2025 models with a Valeo 48 V starter-generator, paired with a 48 V system fault, and blames starter-generator software. CARB requires monitoring of the generator system. Effects range from a MIL to lost charging or no hybrid drive.
- What you may notice
- MIL and hybrid or charging warning on
- Battery no longer charged, start-stop or hybrid drive unavailable
- Vehicle may not reach ready state
- Likely causes
- LikelyInternal failure of the inverter or generator control electronics
- PossibleControl software fault, fixed by an update where the maker provides one
- RareSupply, ground or bus connection to the module faulty
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €150 – €4,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.