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prius loses all power when shutting off

Discussion in 'Gen 2 Prius Main Forum' started by gilga, Sep 4, 2017.

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  1. gilga

    gilga Junior Member

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    This issue has started this week. What I have found is that when I shut off my prius and do not open the door the power to the entire prius will turn off completely meaning no cabin lights, headlights, no light where you insert the FOB, and I cant even lock the doors. The only way to restore power is to open the driver door and close it.

    Once restored the prius will sometimes randomly start as if you pressed the power button and not the gas pedal so the engine wont start. I have to stay around to press the power button again to make sure it is turned off because if I leave the car started then the battery dies. After Ive turned off the prius for the second time there are no more issues until I drive it again.

    I don't think it is a battery issue as I had it replaced with a quality battery last year. I think it might be a fuse.
     
  2. valde3

    valde3 Senior Member

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    This just sounds like 12V battery problem. Even if it’s only a year old it can have problems.

    If the 12V battery is good then it’s very likely the connections. Terminals on battery are clean and tightened (don’t overtighten)? Negative battery cable has good connection to body? Negative cable to ring terminal is tight and not corroded? Connectors on positive terminal are inserted fully?
     
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  3. jerrymildred

    jerrymildred Senior Member

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    +1
    When weird things happen, check the 12V battery and its ground first.
     
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  4. Sam Spade

    Sam Spade Senior Member

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  5. Beachbummm

    Beachbummm Senior Member

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    no its not a fuse, when a fuse blows there is no power, it doesn't heal itself.. has to be replaced..
    could be the switch inside the door going bad or sticking.. but I have not seen it on a prius, my old GM van the radio would not shut off because of the door switch,it was built into the locking mechanism. had to push it up with a screw driver.
     
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  6. gilga

    gilga Junior Member

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    the ground slipped off. very quick fix. thank you guys so much!
     
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  7. bisco

    bisco cookie crumbler

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    that's a new one afair, where is the ground?
     
  8. Coopers ST

    Coopers ST Junior Member

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    Wait so when I get to my destination and push the start button, everything goes off including the radio, that isn't normal?
     
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  9. bisco

    bisco cookie crumbler

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    can you lock the doors?:whistle:
     
  10. jerrymildred

    jerrymildred Senior Member

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    No, the cabin lights should still operate.

    Glad it's fixed. :) I love it when it's easy. Just wish it was easy more often.
    @valde3 & @Sam Spade ... High five! (y)
     
  11. Coopers ST

    Coopers ST Junior Member

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    Oh yes the lights still come on, the radio turns off, windows don't work. So that's normal?
     
  12. bisco

    bisco cookie crumbler

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    and the car won't go!:mad:
     
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  13. jerrymildred

    jerrymildred Senior Member

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    Quite normal. (Except on the Gen 3 at least, the windows will still work after you shut off the car until you open a door. Not sure about Gen 2.

    What the OP had was not normal.
    So I'm totally confused by your initial comment in #8.
     
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  14. Coopers ST

    Coopers ST Junior Member

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    In post 8 I meant the radio shuts off, windows stop working, dash goes out, but the overhead lights come on. I am used to the radio staying on and windows still work till you open a door.
     
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  15. Zizi

    Zizi New Member

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    Hi Gilga, how did u fix it, I have the same issue. Thanks
     
  16. Zizi

    Zizi New Member

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    It is so annoying that I have to slam my Prius door like 5 times to get any light, to start the power or to lock my Prius, or I have to slam the truck, which is even better. Help please

    And the Prius re start now and then and has a message don’t turn off power, no Bluetooth, radios messed up and the clock messed up too!
     
    #16 Zizi, Jul 10, 2019
    Last edited by a moderator: Jul 11, 2019
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  17. PriusCamper

    PriusCamper Senior Member

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    I know this is an old thread but I've been having this exact same problem, except mine fixes itself and car comes back from totally dead if I open and close the right rear passenger door. I inspected and redid all the 12v battery connections last Spring and that solved it, but today the problem came back. So now I'm going to to see if anything is wrong with where the 12v battery connects again. For a while I was convinced that it was the power button itself because it primarily happens on a really fast light push of the button and never happens on a very firm slow intentional push.

    My theory is one of the relays malfunctions when you turn the car off and there is a less than solid connection on the battery. But still not sure yet... If anyone has any thoughts about the details of how a Prius bricks itself when you turn it off and then sometimes randomly turns itself back on to the mode created when you push the power button twice without foot on the brake?

    Sure would like to learn about this phenomenon!
     
  18. jerrymildred

    jerrymildred Senior Member

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    Good starting place. I feel like a broken record because I said something like this yesterday on another thread. That ground connection to the body is not exactly what I would call robust. If it would just fall of completely, that would make it easy, but it just comes loose and then weird stuff happens.
     
  19. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    I say the key is vibration. The contact between the 12v battery and the car is poor. Slamming the door creates enough vibration to temporarily restore the electrical path between the battery and the car. Enough to go into ready mode. And once it's ready, the DC/DC converter will happily keep the car going until you shut down.

    I've seen similar on much lower-tech cars.

    Somewhere in the wire path, something is shaking loose. It may be the clamps on the top of the battery, it may be the far-ends of the battery cables, and it may even be corrosion within the battery cables. I don't generally see that last one in cars with cabin batteries, but with underhood batteries sometimes you'll see the copper strands of the battery cable dissolve into green mush under the insulation. With all of these causes, the electrical path can continue to work part-time as long as something is shaking the car occasionally.
     
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  20. ChapmanF

    ChapmanF Senior Member

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    Worked on a friend's car where one of the battery post/clamp interfaces wasn't as shiny clean as it could have been. Worked just like a self-reset circuit breaker: walk up to the car, open the door, dome light comes on, other lights and stuff work, turn the key to start, starting current heats up that battery clamp and expands it, everything goes dark. Wait like ten minutes, clamp cools down and contracts, lights come back on. :)