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Please help - Coolant System

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by marcylb1, May 18, 2010.

  1. marcylb1

    marcylb1 Junior Member

    Joined:
    May 18, 2010
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    Location:
    southern califronia
    Vehicle:
    2005 Prius
    Model:
    N/A
    I've looked at the info for these codes separately, but I was wondering if anyone could help me figure out what to do about these simultaneous codes...





    P0A93- inverter coolant cooling performance
    P1121- coolant flow control valve


    Can I still drive it? Can I get the parts from the dealer and take to local shop?



    Dealer quoted me $1k to fix, then offered me a 10% discount (so $900). Seems really steep.
     
    #1 marcylb1, May 18, 2010
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    Your car has two separate problems.

    DTC P0A93 means that the inverter cooling system is not working. The most likely reason is a failed inverter coolant pump.

    DTC P1121 means that the engine coolant valve is stuck. This regulates the flow of coolant to the coolant heat recovery system canister and the cabin heater core.

    Between the two problems, DTC P0A93 is more significant. That needs to be fixed immediately. You can drive the car only short distances in the hot summer weather, or risk overheating the inverter which will cause the car to shut down.

    Replacing the engine coolant valve can be done later. The effect of not replacing it means that the engine will take a bit longer to warm up from a cold start. The cabin heater may or may not work.

    If you can find a local shop to replace the inverter coolant pump, that would be fine. I recommend you satisfy yourself that the shop's techs have Toyota hybrid training, as the pump replacement is not necessarily obvious to a tech who hasn't bothered to learn about Prius. I have previously posted how to replace that pump.

    Good luck.
     
    #2 Patrick Wong, May 18, 2010
  3. jdenenberg

    jdenenberg EE Professor

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    Did you recently replace the coolant? These symptoms can be caused by air in the cooling systems.

    JeffD
     
    #3 jdenenberg, May 19, 2010
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