P0A1A: Generator Control Module
Severity: high
What it means: The hybrid system found a fault in the generator control circuit inside the inverter (the motor-generator ECU area).
Safe to drive? No, not for long. Toyota says the car enters fail-safe mode with reduced power, and some cars stall. Have it towed or driven gently straight to a dealer.
Common symptoms
- Red triangle master warning and several warning lights
- Check-engine light
- Reduced power (fail-safe or limp mode)
- Car may shut down or refuse to go into READY
Likely causes, ranked
- Motor-generator ECU fault inside the inverterShop
- Inverter current sensor faultShop
- Failed IPMShop
- Inverter wiring harness faultShop
Vehicle-specific notes
- :
What it means: The hybrid system found a fault in the generator control circuit inside the inverter (the motor-generator ECU area).
Severity: High. Safe to drive? No, not for long. Toyota says the car enters fail-safe mode with reduced power, and some cars stall. Have it towed or driven gently straight to a dealer.
DIY or shop?
Dealer or hybrid shop.
Vehicle notes
- On 2010–2015 Prius and 2012–2017 Prius V, Toyota's bulletins name this code as an inverter fault. Recalls and an IPM warranty enhancement may cover the repair. Check your VIN.
Before you replace parts
- Read all stored codes, including detail (INF) codes on Toyota hybrids.
- Check your VIN for recalls, service bulletins and extended coverage.
- Clear the code only after a repair, then confirm it stays off.
Safety / mechanic note
Verify with a mechanic. Hybrid systems carry dangerous high voltage. A code points to a circuit or system, not always a specific part.