What P0A3C means
P0A3C reports overheating of the inverter that powers drive motor A, usually measured at its IGBT power switches.
How the engine computer detects it
Mitsubishi sets it on the 2023 Outlander PHEV when the front motor control unit reads 166 °C (331 °F) or more at the U-phase upper IGBT for 0.12 s; other switch positions have their own P30xx codes. Honda calls it motor control module overheating and lists it among the codes caused by a cracked solder joint in the 2012-15 Civic Hybrid motor power inverter, covered by a warranty extension. On the 2023-25 Accord Hybrid and 2025-26 Civic Hybrid, Honda links it to a PCU radiator damaged by road debris. P0A78 is the general inverter performance code, P0C11 to P0C13 are phase-specific. Power is cut to protect the inverter.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Hybrid system warning and check engine light
- Strongly reduced drive power
- Coolant loss from the inverter circuit
Common causes
- PCU or inverter radiator damaged or leaking (Honda Accord/Civic Hybrid) Most likely
- Internal inverter defect such as a cracked solder joint (Honda Civic Hybrid 2012-15) Possible
- Low coolant or failed electric pump in the inverter cooling circuit Possible
- Radiator fan not running Less likely
How to diagnose P0A3C
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: inverter, drive motor a, igbt module.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Reading the code
- P
- Powertrain
- 0
- Generic (SAE) code
- A
- Hybrid and electric propulsion
- 3C
- Specific fault
Questions drivers ask
Can I drive with code P0A3C?
No. Pull over as soon as it's safe and switch the engine off. An overheating engine can warp the cylinder head or blow the head gasket within minutes. Don't open the radiator cap while it's hot. Check the coolant level once it has cooled, and have the car towed if the warning comes back.
Will my car pass an emissions inspection with P0A3C?
Probably not in states that test vehicles with an OBD-II scan: an emissions-related code that keeps the check engine light on is usually an automatic fail. Rules differ by state and county, so check yours.
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.