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'08 Prius Shorts out

Discussion in 'Gen 2 Prius Main Forum' started by John Harmon, May 3, 2024.

  1. John Harmon

    John Harmon New Member

    Joined:
    May 3, 2024
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    Location:
    Baltimore
    Vehicle:
    2008 Prius
    Model:
    N/A
    I am having a funny issue, started a while ago and the fix was simple but now it is getting more complex. It started as sometimes the dash wouldn't light up all of the way. Simple fix I would was to unplug the positive auxiliary terminal connector for 30 seconds then turn the car back on once it is plugged back in and it would work. Now it has evolved into the car literally dies. Sometimes when I start my car or turn it off the car shorts out and suddenly turns off and everything goes black. When this happens I do one of two things and then it works. I have to crawl back and bang on the positive auxilary battery connector and it either turns back on. Or I unplug the large white connector cable into it for 30 seconds then the car will start. Sometimes the cars dash will partly light up and then not turn off so I have to do those same steps. Getting annoying as I cannot smog my car so that I can renew the registration. Really need help, considering replacing the positive terminal connector to fix it.
     
  2. Tombukt2

    Tombukt2 Senior Member

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    Nov 29, 2020
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    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    No you have the CM monitor issue that is the dash in front of you that shows you your speed gas gauge what your transmissions doing that sort of thing when that starts to go funky because of the three capacitors that need to be replaced on the board then you have to hold the button down to make the car go off touch it quickly to light up the car without doing other things like making it ready so on and so forth very common read about it for a week in this very chat space people have had this issue for as long as the cars have been made probably. The answer is is the dashboard top comes off flips over goes out on your bench or in the trunk and you disassemble the plastics and take out the board try to solder on the capacitors yourself or you send it down to Texas hybrids with your information VIN number and mileage they send you back a new one literally that they've made and you send them your old one and their prepaid mailer and I think it all cost $150 bucks after the return of your old unit. Put that in your car pretty much your problems are over as far as that issue.
     
  3. dolj

    dolj Senior Member

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    May 14, 2012
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    Location:
    Wellington, New Zealand
    Vehicle:
    2007 Prius
    Model:
    N/A
    You have a janky connection at the 12 V battery and a failing/failed CM. The CM can be repaired at Texas Hybrid Batteries if you are happy to remove some of the dash and remove the CM.

    If you are removing and replacing the 12 V battery clamp without using a wrench to loosen and tighten the clamp, you are not getting a good connection which is causing you electrical problems. Loosen the clamp with a wrench before removing it and tighten again with the wrench when replacing to ensure a good battery connection.

    I hope that helps.