P0A93 on Lexus
Inverter Cooling System Performance
P0A93 on Lexus vehicles indicates inverter cooling system performance. Au7o has documented this code across 2 Lexus models — most commonly on CT, GS. This hybrid/electric code means the computer detected that the inverter's cooling system isn't performing well enough to keep the inverter at a safe temperature. The inverter converts high-voltage DC battery power to AC for the drive motors (and back), and it has its own dedicated liquid-cooling loop with an electric pump. When coolant flow or temperature stays out of range — meaning the inverter is overheating or at risk of it — this code sets. It commonly points to a weak inverter coolant pump or low/blocked coolant, and continuing to drive risks expensive inverter or hybrid-system damage. Typical repair costs on Lexus range from $400 to $1,200, depending on the specific model and root cause.
Common Causes of P0A93
- •Failed or weak inverter (high-voltage) coolant pump
- •Low coolant level or air pocket in the inverter cooling loop
- •Coolant leak in the hybrid cooling system
- •Clogged or restricted inverter cooling radiator/heat exchanger
- •Kinked or blocked coolant hose
- •Faulty coolant temperature sensor or pump wiring
- •Contaminated or degraded coolant
P0A93 on Lexus by Model
Lexus CT(1 issue)
- Electric Water Pump Premature Failure2011-2017
The electric water pump on the CT200h hybrid system fails prematurely, causing coolant circulation loss for the hybrid inverter and electric motor. Unlike conventional belt-driven water pumps, this is an electric unit that controls coolant flow to the high-voltage hybrid components. Failure can lead to hybrid system overheating and shutdown.
Lexus GS(1 issue)
- Hybrid Inverter Coolant Pump Failure - GS 450h (P0A93)2007-2011
The GS 450h carries a second, completely separate cooling circuit for the power inverter, consisting of an electric water pump, its own radiator and a fan. That electric pump fails - it is a known wear item on the S190 hybrid - and when circulation stops the inverter overheats. The car sets P0A93 (inverter cooling system performance), lights the master warning and hybrid system warning, and typically drops into a limited-power limp mode or refuses to enter READY. Because the inverter is a five-figure component, a failed $200-$500 pump that is left unaddressed is the cheap failure that causes the expensive one. Low inverter coolant level in the dedicated reservoir produces the same code and should be checked first. This is exclusive to the GS 450h - the GS 350, GS 430 and GS 460 have no inverter circuit.
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View P0A93 across all makes →Frequently Asked Questions
What does P0A93 mean on Lexus?▼
P0A93 stands for "Inverter Cooling System Performance." This hybrid/electric code means the computer detected that the inverter's cooling system isn't performing well enough to keep the inverter at a safe temperature. The inverter converts high-voltage DC battery power to AC for the drive motors (and back), and it has its own dedicated liquid-cooling loop with an electric pump. When coolant flow or temperature stays out of range — meaning the inverter is overheating or at risk of it — this code sets. It commonly points to a weak inverter coolant pump or low/blocked coolant, and continuing to drive risks expensive inverter or hybrid-system damage. On Lexus specifically, this code is documented across 2 models.
What causes P0A93 on Lexus vehicles?▼
Common causes on Lexus: Failed or weak inverter (high-voltage) coolant pump, Low coolant level or air pocket in the inverter cooling loop, Coolant leak in the hybrid cooling system, Clogged or restricted inverter cooling radiator/heat exchanger, Kinked or blocked coolant hose. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0A93 on a Lexus?▼
Repair costs on Lexus range from $400 to $1,200, depending on the specific model and root cause.
Which Lexus models have P0A93 documented?▼
Au7o has documented P0A93 on 2 Lexus models: CT, GS.