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2002 Prius not starting

Discussion in 'Generation 1 Prius Discussion' started by Alex2002Prius_, Oct 4, 2022.

  1. Alex2002Prius_

    Alex2002Prius_ New Member

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    Vehicle:
    2002 Prius
    Model:
    N/A
    I have a 2002 Toyota Prius with approximately 170,000 miles on it. On occasion lately it has troubles starting. When this happens the lights on the dash all turn on but the engine does not engage. I also get the red triangle on the dash. After a couple tries the car will start and seemingly drive fine. On mornings when this happens I will have no issues driving home ~8 hours later. This issue may return the next morning or the car will be normal for over a week.

    I have a scanner and got the following codes recently: P3101 (engine system), P3000 (battery control system), P3001 (battery ECU).

    Another piece of information that may be relevant is that I do have a fairly recently installed green bean battery. Could this be the battery or battery ECU, or is it likely something related to the engine that is causing it to not start?

    Thank you for your help!
     
    #1 Alex2002Prius_, Oct 4, 2022
  2. ammdb

    ammdb Active Member

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    Sounds like a weak 12V battery to me.
     
    #2 ammdb, Oct 4, 2022
  3. Josey

    Josey Active Member

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    Have you gotten in touch with greenbean tech support? I'll never count out a 12V battery problem, so checking it out can't hurt. (Do you own a basic volt meter?) But the P3000 and P3001 implicate the HV battery ECU which is part of the HV battery unit. I would have started with greenbean rather than internet discussion boards.
     
    #3 Josey, Oct 4, 2022
  4. AlexY

    AlexY Member

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    Is it something like 50 F or less temperature in the morning? It can be throttle body need cleaning
     
    #4 AlexY, Oct 8, 2022
  5. Trombone

    Trombone Member

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    Location:
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    Vehicle:
    2002 Prius
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    N/A
    The sounds exactly like the behavior of my '02. The original ECU apparently did not take into account how low ambient temperature would delay engine start time. Early on in the history of the Classic there was a factory recall that switched out the ECU for one that corrected the problem. After checking out the 12 volt battery, as others have already advised, I'd look into the GreenBean ECU aspect. Good luck, and let us know how this all turns out.

    As AlexY noted above, and also in my experience, it had to be fairly chilly out (i.e., below freezing) for the original ECU not to start the car.
     
    #5 Trombone, Oct 8, 2022
    Last edited: Oct 8, 2022
  6. Alex2002Prius_

    Alex2002Prius_ New Member

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    Location:
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    Vehicle:
    2002 Prius
    Model:
    N/A
    Hi everyone, thank you for your replies. I borrowed a voltmeter today to check my battery. It was 12.3V at rest and then bounced up to 13.8V under load, so I think the 12V battery is good. I bought some cleaner for the throttle body to give that a try soon. It seems like a good idea to do regardless.

    I do notice this on slightly colder mornings around 50-55F. It started up with no issues on the weekend (mid-morning when it was slightly warmer) but I had issues at 8am today.

    I will contact Green Bean as well. I see online that they "upgrade" the ECU when they do the swap. This may be my problem.

    I'll report back soon.
     
    #6 Alex2002Prius_, Oct 10, 2022
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