OBD-II Code

P0A93

Severity

Not yet reviewed

Nobody on our side has assessed this code yet, so we are not going to guess at how serious it is.

Can you drive it

We cannot say

Treat it as unknown until a shop reads it with live data. If the check-engine light is FLASHING, stop driving as soon as it is safe to — that means an active misfire, whatever the code.

Indicative cost (USD)

$180–$850

From this code's diagnostic notes. Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.

P0A93 indicates the inverter cooling system is not performing to spec — specifically, the inverter coolant temperature is climbing faster than the BECM's thermal model predicts given commanded pump speed and ambient conditions, or the temperature is exceeding the high-side threshold (65C on Prius, 70C on Ford eCVT) during normal operation.

How a shop works this

Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.

Note every code that is set, not just this one.
Codes that appear together usually narrow the cause faster than any one of them read alone.
Read the freeze frame — the conditions the fault was recorded under.
Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.
Confirm the fault is current rather than history.
Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.
Then follow the diagnostic notes further down this page, in the order they are written.
They are written in the order a shop works this code, cheapest checks first. Where they name a component, inspect its wiring and connector before replacing it.

If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.

Common symptoms

Check engine light

Read the full diagnostic procedureP0A93 indicates the inverter cooling system is not performing to spec — specifically, the inverter coolant temperature is climbing faster than the BE…+

Cheapest-first diagnostic ladder

visually check the inverter coolant reservoir level FIRST — this is separate from the engine cooling system on Prius/Camry Hybrid/Highlander Hybrid and shares with engine coolant on Ford Escape/Fusion Hybrid;
Toyota's inverter loop uses pink Toyota Super Long Life.
Listen for the electric inverter coolant pump (Toyota P/N G9020-47031 is the famous Prius part) running with key-on engine-off — you should hear a quiet whirr from the pump for 30-60 seconds; silence means a failed pump, which is the #1 cause of P0A93 on Prius Gen 2/3.
Caveat: P0A93 on Prius Gen 2 with original-mileage coolant pump should be assumed to be the pump until proven otherwise — the failure rate is so high that Toyota issued TSB EG024-11.

Vehicle-specific patterns2004-2009 Toyota Prius Gen 2 (NHW20) — inverter coolant pump (G9020-47031) failure at 100K-150K miles is so common that the aftermarket sells a $90 O…+

2004-2009Toyota Prius Gen 2 (NHW20) — inverter coolant pump (G9020-47031) failure at 100K-150K miles is so common that the aftermarket sells a $90 OE-spec replacement.
2010-2015Toyota Prius Gen 3 (ZVW30) — revised pump P/N G9020-47030 still fails but at higher mileage.
2007-2011Toyota Camry Hybrid / Highlander Hybrid — shared inverter pump architecture, same failure mode.
2013-2018Ford Fusion Hybrid / C-Max — inverter coolant loop shares with engine loop, P0A93 often caused by a stuck-closed thermostat.

Estimated repair$180 to $850.

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