2005 Prius ICE not starting, no ready mode, P3000 and U0100

Discussion in 'Gen 2 Prius Main Forum' started by alleneatsapples, Oct 27, 2021.

  1. alleneatsapples

    alleneatsapples New Member

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    Vehicle:
    2010 Prius
    Model:
    III
    I really appreciate the community we have here and our ability to help each other out. I am grateful for all of you. Thank you.

    I just bought a 2005 Prius project with a U0100 code and a P3000 code with red triangle. Car will not go into ready mode, not reverse or drive, and no engine startup. From my experience, the gas engine turns on even without the hybrid battery working. Any ideas and comments would be appreciated!

    Things I have done so far:

    -Replaced the 12v battery
    -Tried clearing codes. Immediately the red triangle comes back.
    -Cleaned the MAF with MAF cleaner.

    Thanks again! Any ideas are super appreciated!
     
  2. Aegean

    Aegean Active Member

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    Location:
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    Vehicle:
    2006 Prius
    Model:
    ----USA----
    Is the battery safety plug installed correctly with 3 steps?


    What about disconnecting the 3-way control valve and try? see post #18
    Codes U0100 and P3000 | PriusChat
     
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  3. SFO

    SFO Senior Member

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    You will need a HV battery with enough voltage to turn over the gas engine, as the engine doesn't start via the 12v battery like other cars.

    Given your location and potential for cabin leaks/humidity, you might try checking for corrosion in the HV battery ECU plug / voltage sense harness connector, and again at the white plug near the HV battery fan (right side of the fan in the image below).

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  4. mr_guy_mann

    mr_guy_mann Senior Member

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    First you might want to check every fuse on the car- that might be the cause for your U0100 (missing power to a control unit). You really should have a scantool that can communicate with all the ecu's on a Prius to check codes and data. P3000 is a code that says "hey, there's something wrong in the HV battery ecu- go look over there for codes". So you need to be able to get codes from the battery ecu (most generic scanners can't) Many here get a mini VCI cable along with a bootleg copy of Toyota's Techstream diagnostic software and install it on an old windows laptop.

    Posted via the PriusChat mobile app.
     
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