09 prius turns back on after turning it off

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Eunhon, Aug 26, 2020.

  1. Eunhon

    Eunhon Junior Member

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    So my prius started doing this 3 weeks ago. I would turn it off and then sometimes itll turn itself back on in accessory mode. One time i turned it off and sat in the car for like 10 minutes, it turned it self back on. Doesnt happen every time but it does happen often enough its messing up stuff like resetting my miles meter in the energy monitor and sometimes itll turn off my AC when it turns it self back on. Heres a video

     
    #1 Eunhon, Aug 26, 2020
    Last edited by a moderator: Aug 26, 2020
  2. valde3

    valde3 Senior Member

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    Try to turn off the smart key system and only use the key in the slot. If you take the key out it can't turn back on? So it's just peeping? Or does it still turn back to ign-on?
     
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  3. Diemaster

    Diemaster Active Member

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    Just a guess. The power button is physically or electrically sticking. So it thinks your holding the button down?
     
  4. valde3

    valde3 Senior Member

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    Basically what the test on my previous post is testing. If control unit sees the button pressed without the key in it peeps. If it's a problem with relay control unit etc. it will still power on.
     
  5. Steve Lavsa

    Steve Lavsa New Member

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    Mines doing same thing there has been a bunch of posts about this with no confirmed resolutions so I'm bringing them back from the dead. Did you ever figure out what was going on? turn it off, and it turns back on and climate, clock, odometers reset.
     
  6. dolj

    dolj Senior Member

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    Your issue sounds like a 12 V power supply issue to me, in that the power is intermittently going on and off. Check all the connections at the 12 V battery in the back. All three (the positive connection on the battery, the negative on the battery, and the ground connection to the car body) should be clean (free of all corrosion) and tight.

    Check that out and post back if there is no change.
     
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