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OBD-II · Engine and powertrain (P)

P0A93

Inverter cooling system performance

What it means

The coolant circuit that cools the hybrid/EV inverter is not cooling it properly.

Symptoms

  • Hybrid/EV warning light
  • Reduced power
  • Car may shut down if the inverter overheats

Likely causes, most likely first

Likely causes, most likely first
No.Cause
01failed inverter coolant pump (common on older Toyota/Lexus hybrids)
02low inverter coolant level or leak
03air trapped in the inverter coolant circuit after work
04blocked radiator

What to check, step by step

  1. 01Check the inverter coolant level (separate reservoir on many hybrids)
  2. 02With the car in READY, check the coolant is moving in the reservoir or that the pump runs
  3. 03Check for leaks
  4. 04Bleed the circuit correctly after any coolant work
  5. 05Replace the pump if it is not running with good power and ground