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Master Warning light on 2002 toyota Prius

Discussion in 'Generation 1 Prius Discussion' started by Gregg zalewski, Jul 2, 2020.

  1. Gregg zalewski

    Gregg zalewski New Member

    Joined:
    Jul 2, 2020
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    Location:
    San Antonio
    Vehicle:
    2002 Prius
    Model:
    LE
    I am in need of serious help. My car ran fine yesterday morning then in when i tried to go to work no power. I drove it home. The Master Warning light on, engine light, and the Cloud Exclamation light on as well. I just returned from the Toyota dealership and thry said it was burning oil (i doubt it), low on oil and wanted me to get a new engine. Im like ya right. So i wasted $135 on a diagnostic. They cleared the codes and i drove it home without issues. Then i tried to start it again and it cranked then died. The same lights came back on. Im told it can be various things Inverter, auxiliary battery, even the pedal. Ive never worked on hybrid before and im not rich. Please guidance into this matter.
     
    #1 Gregg zalewski, Jul 2, 2020
  2. Josey

    Josey Active Member

    Joined:
    Jun 10, 2019
    287
    108
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    Location:
    Virginia
    Vehicle:
    2003 Prius
    Model:
    One
    You need a Techstream / Mini--VCI. It's a knock off of the Toyota code reading diagnostic system. Search the forum for it and then you'll end up on eBay or some such. You won't get anywhere until you can read all diagnostic codes from the car...for which you want a Techstream
     
    #2 Josey, Jul 2, 2020
  3. dabard051

    dabard051 Tinkerer-in-Charge

    Joined:
    May 19, 2009
    241
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    Location:
    Rochester, NY USA
    Vehicle:
    2002 Prius
    Model:
    N/A
    Josey is right; the correct way is to get a Techstream and find out ALL the toyota codes that are being produced.

    In the meantime, any regular OBDII code reader (Harbor Freight, AutoZone, Advance Auto, NAPA, Wal-Mart) will tell you most of the engine codes and get the repair process started.

    From your problem description, I'm gonna GUESS that the electric inverter coolant pump has failed and that the Master Warning Light, Check Engine etc. was for the inverter going overtemp. Why? You got the fault code, went to dealer, dealer cleared codes & lightened your wallet, and you were able to drive home WITH NO ISSUES. Then when you restarted, the codes came back because the coolant wasn't flowing.
    There are other threads on this site with how to check this out. Keyword is "inverter cooling pump".
    If this pump fails, it sets the master warning light with a Prius-specific fault code which may NOT show up on a regular OBDII reader (P0A93)... the part number is either G9020-47020 or G9020-47022, about $150 or so, only available through Toyota. It's a 15 minute repair, IF this is your issue.

    Good luck in the problem solving...
     
    #3 dabard051, Jul 13, 2020
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