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Self Starting Prius?

Discussion in 'Gen 2 Prius Main Forum' started by qmanqman, Feb 23, 2022.

  1. qmanqman

    qmanqman Active Member

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    I helped a buddy buy a 2007 for his daughter. Really nice clean car. He came home the other day and found it was running. When he asked her about it she told him that it has been starting itself from time to time and that she read it is a known problem.

    I didn't believe it so I did a search and sure enough there are a lot of threads on this here website. I read through a number of them and there doesn't seem to be anyone who has solved this problem. One guy seems to have made the problem go away by putting in a new 12V battery. Can I ask y'all if anyone has had and solved this issue?
     
    #1 qmanqman, Feb 23, 2022
    Last edited: Feb 23, 2022
  2. PriusCamper

    PriusCamper Senior Member

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    Yes new 12v can resolve it... Also the circuitry on top of the 12v battery if not bolted down all the way or plugs have become loose can also cause this problem.

    When you turn off the car the shift position light on the combination meter on the dash should be the last light to go off in the shut down sequence. If the whole screen goes blank at the same time and the car loses all power, even cabin lights and door locks, the shut down sequence went wrong and car might turn itself back on again in the same way it does when a dead 12v finally has been charged up.

    Also similar, but probably not related, if combination meter no longer lights up, there's a capacitor in it there that needs to be replaced. When that capacitor fails and meter doesn't light up you get similar problems with the car not shutting down correctly.
     
    #2 PriusCamper, Feb 23, 2022
  3. AlexY

    AlexY Member

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    Starting itself? Never had this or never heard about it. Is it model with smart key? Can't see any other option as you can't remove fob from socket if car is in ready state. Only model with smart key can be started remotely if someone with stuff used to steal such car is playing with it. This is what I know about it but maybe I don't know about something.
     
    #3 AlexY, Feb 24, 2022
  4. qmanqman

    qmanqman Active Member

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    Google this and read all about it:

    "does a gen 2 prius turn on by itself"
     
    #4 qmanqman, Feb 24, 2022
  5. mr_guy_mann

    mr_guy_mann Senior Member

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    Without a bunch more information (and maybe a video), all anyone here can do is guess.

    Guess #1, somehow the car isn't being powered off correctly (ie, it's still in a "ready" mode where the inverter and HV system is on and the engine will run when needed to recharge the HV battery). Don't know if people aren't familiar with the Prius, don't know if you have a faulty dashboard cluster (Combination Meter - aka speedometer)

    Guess #2, there's an aftermarket remote start system (somehow) wired into the Prius and that's what doing it.

    Posted via the PriusChat mobile app.
     
    #5 mr_guy_mann, Feb 24, 2022
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