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Prime 12v swap. Still getting the Christmas tree

Discussion in 'Prime Care, Maintenance and Troubleshooting' started by FlyMode, May 16, 2024.

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  1. FlyMode

    FlyMode Junior Member

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    So my 2018 prime had the much dreaded Christmas tree caused by the dying 12 volt battery. I swapped it out just over a month ago and all was well until today, I was driving back home about 120 km into the journey and the Christmas tree came back. once I got home I checked the voltage and the resting voltage was 12.6, which I believe is good and healthy. Does anyone have any idea what the underlying issue could be or have any tips?!

    Thanks
     
    #1 FlyMode, May 16, 2024
  2. FuelMiser

    FuelMiser Senior Member

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    Do these one at a time. If symptoms better, stop.
    1. Check the tightness of the battery connections. 2. Have the new battery load tested. 3. Remove the negative terminal for 30 seconds and reconnect.
     
    #2 FuelMiser, May 17, 2024
  3. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    “Christmas tree” being lights on the dashboard? Get the codes read?
     
    #3 Mendel Leisk, May 17, 2024
    Danno5060 and Brian1954 like this.
  4. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    There's a really long list of things that can cause your dash to light up like a Christmas tree.

    I agree with FuelMiser, worth checking the tightness of the connections- but loose battery terminals don't usually trigger error codes so there's not a lot of percentage in it.

    Time to get the diagnostic codes read and find out what is really going on.
     
    #4 Leadfoot J. McCoalroller, May 17, 2024
  5. FlyMode

    FlyMode Junior Member

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    I will start here. I drove to work and no issues popped up at all so that's a good start . Easy enough to check these through.

    Yeah I have to purchase my own reader. Every dealership I call in the area is saying 2-3 weeks for even a basic appointment like that. Which is a shame I bought a Toyota for reliability and service. I understand everyone's busy but a quick code read can't even be done for 2 weeks seems a bit odd.

    As soon as I mention warranty to the dealership they instantly change their tone. I've called the four closest to me.
     
    #5 FlyMode, May 17, 2024
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  6. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    GTA is Greater Toronto Area, Ontario, Canada, I'm guessing? A clear/complete explanation of your location will help responders.
     
    #6 Mendel Leisk, May 17, 2024
  7. FlyMode

    FlyMode Junior Member

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    Hey Mendel,

    Yes I'm north of Toronto about 45 minutes located in King Township. Ive reached out to dealerships all the way from ajax, to maple, Whitby, Brampton, Mississauga, Barrie.

    Even if it's an emergency or catastrophic failure I'd have to schedule an appointment with them and the car would sit for roughly 2-3 weeks depending on the location.
     
    #7 FlyMode, May 17, 2024
  8. bisco

    bisco cookie crumbler

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    that's the way it is pretty much everywhere these days. some auto parts stores offer free code reading, but they don't always pick up the codes, depending on what ecu is reporting.
    there's a thread here on autel scanners which can read everything
     
    #8 bisco, May 17, 2024
  9. Brian1954

    Brian1954 Senior Member

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    #9 Brian1954, May 17, 2024
  10. FlyMode

    FlyMode Junior Member

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    I have a Bluetooth reader, when I originally had the issue it was an absolute list of codes so I came here and between this forum and a buddy I figured it was the 12v. Once I swapped the issue went away. It hasn't been back today so maybe a fluke? If not I'll reread the codes and see what more I need to do
     
    #10 FlyMode, May 17, 2024
  11. Brian1954

    Brian1954 Senior Member

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    What Bluetooth OBD2 adapter and app do you have. Most are not capable of reading all the trouble codes in your Prius. Read post #1 in the thread that I linked to in my previous post.

    If warning lights are on, there are trouble codes that need to be read. I predict the warning lights will return, then come back and post what trouble codes you found.
     
    #11 Brian1954, May 17, 2024
  12. FlyMode

    FlyMode Junior Member

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    It's a bluetooth OBD2 link unit and the app I believe is called Car OBD plus. I'll have to take a look but once they come back I'll post the screenshot of all the codes
     
    #12 FlyMode, May 17, 2024
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