Powertrain, generic · Hybrid propulsion

P0A93 Inverter A Cooling System Performance

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

The power inverter of a hybrid has its own coolant circuit with an electric pump, radiator and fan, separate from engine cooling. 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.

Likely causes

Electric inverter coolant pump failed or seized
Low coolant or air in the inverter circuit
Pump wiring, fuse or relay fault
Radiator fan not running or radiator blocked

Symptoms

  • Hybrid system warning and MIL
  • No EV mode, reduced power
  • Vehicle may not start or may stall

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–800
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

inverter cooling system

Related codes

P0C73P0AEEP0A94

References: static.nhtsa.gov, static.nhtsa.gov, law.cornell.edu.