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Interior lights do not go on

Discussion in 'Gen 4 Prius Care, Maintenance and Troubleshooting' started by csk47, Nov 20, 2020.

  1. jerrymildred

    jerrymildred Senior Member

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    It's a bad switch. Might be dirty. Might need the contact bent a little bit. I'd take it apart and look.
     
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  2. Khristina

    Khristina Junior Member

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    Ok. Thank you!
     
  3. Doug McC

    Doug McC Active Member

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    It could very well be a bad switch but I would eliminate simpler problems before tearing it apart. You probable already know that it is a 3 position switch such that when it is pushed toward the drivers side, the light is off all the time; when it is in the center position, it operates automatically based on the doors, timers, etc.; and in when pushed to the passengers side it is basically on all the time (in 2022 model it will eventually shut off, but not for quite a while).
    Assuming you have it in the center position when you are pressing on it (and not clicking it to the right or the left) then it could be broken. However, the first thing I would check is your vehicle customization settings to be sure somehow they weren't changed to effect the auto (center) operation (in the 2022 model you can actually set it to be off). If the settings are correct, then I would try operating it through all three positions several times. It is a mechanical/electrical switch and being 6 to 7 years old it could be just slightly corroded or dirty, and cycling it on and off may clean it up.
    If that doesn't take care of it then I would assume the switch is bad and will need to be removed, but make sure you either pull the fuse for the circuit or disconnect the battery to avoid damaging any of the electronics since that circuit is connected to several timers.
    Hope this helps.
     
  4. jerrymildred

    jerrymildred Senior Member

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    This?
    Screen Shot 2022-03-31 at 8.23.00 AM.png

    That's a "dealer only" setting meaning you need to do it through the OBDII. And if it was set to off, it would always be off.
     
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  5. Doug McC

    Doug McC Active Member

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    That’s a good point, and it is unlikely that the dealership would do that without being asked, but still worth checking. OR, FWIW, I was able to disable the light coming on when we approached the vehicle WITHOUT going through the OBDII AND was unable to do things through the OBDII that I should have been able to. I can’t explain it, but that is what I have experienced. So my suggestion is to check the vehicle settings and just make sure.
     
  6. TonyH56

    TonyH56 New Member

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    I gets this same issue in my 2017 Prius PHV - when I put a bit of pressure on the switch in the roof (not the door sensor) I can make it work. I’m assuming then that this is an issue in the roof switch - did you get a fix?
     
  7. TonyH56

    TonyH56 New Member

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    OK so I think I fixed it. I partly removed the trim around the switch (how - see this YouTube video
    ) then gently pulled out the rocker part of the switch. One of the contacts was a bit dirty so I cleaned it. Just to be sure I squeezed the two contacts together a bit to help them make contact, re-inserted the rocker carefully and tested it. Voila! it now works as intended. Replaced the trim and it's still OK. Will see how long this lasts.
     
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  8. Khristina

    Khristina Junior Member

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    I recently went to Toyota to get an oil change and asked them about it. I went at 4pm so they said they would check it out another day. That was about two weeks ago. I’ll be back there soon and I’ll let you know.
     
  9. jlhopes

    jlhopes New Member

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    just wondering if you were able to fix this problem, and how you did it. I am having the same issue on my 2017 Prius. Thanks!
     
  10. jlhopes

    jlhopes New Member

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    Just wondering if you were able to fix this problem, and how you did it. I am having the same issue on my 2017 Prius. Thanks!
     
  11. barry mullinax

    barry mullinax Junior Member

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    I have the exact same issue. Not sure if the switch connection is loose or what but I hope to look further into it this weekend
     
  12. Khristina

    Khristina Junior Member

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    Sorry it’s been so long. I did find a video to take apart the overhead light panel and took a Q-Tip and cleaned everything, the connectors & everything in the surrounding area. It worked! Now I want to replace the current bulbs with LED lights. I just looked at a video of someone changing their own lights to get the panel open and it was a breeze. Now, on to my next progect.
     
  13. AJ11235

    AJ11235 Junior Member

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    I have the same issue in my 2016 Prius, will have to take apart the ceiling light assembly and clean the contacts.