What P0A93 means
The power inverter of a hybrid has its own coolant circuit with an electric pump, radiator and fan, separate from engine cooling.
How the engine computer detects it
P0A93 is set when this circuit does not cool as intended. CARB lists inverter thermal management among the components that hybrid OBD must monitor. Hyundai documents the code for the 2011 Sonata Hybrid (bulletin 14-HC-001), assigning it, like P0C73, to the electric water pump; symptoms include a hybrid warning, no EV mode and poor acceleration. Toyota recalled 2004–2009 Prius models (12V-536) because the inverter water pump could fail and cause a stall; that notice does not name a code. A leaking or air-locked circuit should also be checked.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Hybrid system warning and MIL
- No EV mode, reduced power
- Vehicle may not start or may stall
Common causes
- Electric inverter coolant pump failed or seized Most likely
- Low coolant or air in the inverter circuit Possible
- Pump wiring, fuse or relay fault Possible
- Radiator fan not running or radiator blocked Less likely
How to diagnose P0A93
- 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 cooling system.
- 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.
Vehicles that report P0A93 most
| Vehicle | Years | Reports | Share | Median miles |
|---|---|---|---|---|
| Toyota Prius | 2004–2009 | 5 | 69k |
Counts of owner complaints to the NHTSA that mention P0A93 (6 in total), not failure rates: popular models get more complaints simply because more of them are on the road. Models with fewer than 3 complaints are left out.
Reading the code
- P
- Powertrain
- 0
- Generic (SAE) code
- A
- Hybrid and electric propulsion
- 93
- Specific fault
Questions drivers ask
Can I drive with code P0A93?
If the car drives normally, drive gently to a shop that services hybrids. If it shows a hybrid system warning, loses power or won't go into Ready, pull over and have it towed. Never touch orange high-voltage cables.
Will my car pass an emissions inspection with P0A93?
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.