P0A93 Hybrid inverter cooling system performance problem

P0A93 inverter cooling system performance

Severity not verified — if the car runs badly, have it inspected

No manufacturer document was read for how serious P0A93 is. Owner complaints describe loss of power while driving and a warning light, but that is not an OEM severity ruling.

Safety-critical system: explanation only, no DIY steps. Source: how we rate severity

P0A93 in short

P0A93 means the hybrid system sees the inverter cooling system not working as intended. On Toyota hybrids the owner complaints we read point to the inverter coolant pump. Some drivers lost power while driving. Treat it as urgent and have a hybrid-trained shop check it; do not keep driving with warning lights on.

On a Toyota hybrid the inverter, which converts the high-voltage battery current for the motors, has its own coolant loop with an electric pump, radiator and fan, separate from the engine. The hybrid control computer watches the inverter temperature and coolant behavior and sets P0A93 when cooling is not performing.

Prius and Highlander Hybrid complaints show dealers and shops finding a failing inverter water pump with P0A93, sometimes with other hybrid codes (P0A05, P0A08), warning lights and a loss of power while driving.

The inverter is part of the high-voltage system, which can seriously injure or kill. This page explains the code only; diagnosis and repair belong with a technician trained on hybrid high-voltage systems.

Most likely causes

  1. Inverter coolant pump failing

    Supported by vehicle data
    Why it ranks here
    Prius and Highlander Hybrid complaints record P0A93 with the inverter water pump found faulty or replaced.
    What would change this
    Rises if the pump does not run when commanded by the hybrid scan tool. Falls if the pump runs and the coolant flow is normal.

  2. Air or low coolant, or a fan or radiator problem in the inverter loop

    Possible — needs testing
    Why it ranks here
    The reference page describes the code as a cooling performance fault; the loop includes pump, radiator and fan. We read no source for the specific condition.
    What would change this
    Rises if the pump works but the temperature still climbs.

  3. Detached coolant hose (Kia Niro plug-in hybrid only)

    Supported by vehicle data
    Why it ranks here
    Kia bulletin TSBELE161 says a detached onboard charger coolant inlet hose can set P0A93 on the 2018-2019 Niro PHEV.
    What would change this
    Rises on an affected Niro with a coolant warning. Not relevant to Toyota.

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Have a hybrid-trained shop read the hybrid system codes and test the inverter coolant pump and cooling loop with a hybrid scan tool.

    Best left to a shopTool: hybrid-capable scan tool

    Warning:High-voltage components and orange cables can cause fatal shock. Do not open or touch them. Only trained technicians should work on them.

Symptoms

  • Check engine, master caution or hybrid warning lights
  • Loss of power or the vehicle shutting down while driving Gets more serious: stop and have it checked.

How to fix

This is a safety-critical system, so we explain the code but don't give repair steps. Have it inspected by a qualified technician.

On your vehicle

Toyota

Kia

  • 2018–2019 · Niro

    Supported by vehicle data

    Kia bulletin TSBELE161 links P0A93 (with P0A3C and P0A3E) to a detached onboard charger coolant inlet hose on the Niro plug-in hybrid. Whether it is still current is not verified.

  • TSBELE161Status unverified

    Coolant leak: onboard charger inlet hose detaching (SA365)

    2018–2019niro · issued · NHTSA 10152899

    If the charger coolant inlet hose detaches, P0A93, P0A3C or P0A3E may set along with an inverter coolant warning; a spacer is installed at the hose.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Ford

  • 2022–2023 · F-150

    Possible — needs testing

    Ford SSM 52213 covers P0A93:96 stored in the DC/AC converter module with a service message and no effect on operation; a different module from the hybrid inverter. Whether it is still current is not verified.

  • SSM 52213Status unverified

    DCACA inverter service message with P0A93:96

    2022–2023f-150 · issued · NHTSA 10249432

    A dealer-service message with P0A93:96 stored in the DC/AC converter module, which may be due to software and has no effect on operation. This is a different module from the Toyota hybrid inverter.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

No curated relationships for P0A93 yet.

All Hybrid and electric drive codes

P0A93 questions

Is it safe to drive with P0A93?

We found no manufacturer guidance. Owners report losing power while driving, so have it checked promptly by a hybrid-trained shop.

Sources and review

  1. NHTSA complaint ODI 10354533 (2005 Toyota Prius) — NHTSA Office of Defects Investigation
  2. NHTSA complaint ODI 10715789 (2006 Toyota Highlander Hybrid) — NHTSA Office of Defects Investigation
  3. P0A93 (347) Inverter Cooling System Performance — The Automotive Technician (tat.net.au)
  4. Kia TSBELE161: 2018-2019 Niro PHEV coolant leak, onboard charger inlet hose detaching (SA365) — Kia America ,
  5. NHTSA complaint ODI 10332367 (2004 Toyota Prius) — NHTSA Office of Defects Investigation
  6. Ford SSM 52213: 2022-2023 F-150 and 2023 Super Duty with DCACA inverter, service message with DTC P0A93:96 — Ford Motor Company ,
Last reviewed
Written by
Saurabh K.
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