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Disconnected battery, not pre-collision and other warning systems not working...

Discussion in 'Gen 4 Prius Main Forum' started by GRF819, Oct 30, 2022.

  1. GRF819

    GRF819 Junior Member

    Joined:
    Sep 23, 2017
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    Location:
    Los Angeles
    Vehicle:
    2007 Prius
    Model:
    Two
    As I have done with previous Prius models, I disconnected the battery because I was going away for 2.5 months. When I returned, I hooked up the battery, which seemed fine, but the physical warning systems, like pre-collision system, do not work. I have checked to make sure they are on. Any guesses as to the problem? Thanks!
     
    #1 GRF819, Oct 30, 2022
  2. CooCooCaChoo

    CooCooCaChoo Active Member

    Joined:
    Jan 7, 2015
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    Location:
    Cow-lee-fornia
    Vehicle:
    2023 Prius
    Model:
    LE
    Are they throwing error codes? If not, how did you determine that they are not working?
     
    #2 CooCooCaChoo, Oct 31, 2022
  3. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
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    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Just in case: check voltage of the 12 volt, with a digital multimeter, first thing on the morning. If practical, pop the hood the previous evening, or at least enter car from passenger side to pop hood (avoids waking up brake system, dropping volts slightly). Post reading; anything over 12.5 would be satisfactory I’d think, 12.7 or higher is tip top.
     
    #3 Mendel Leisk, Oct 31, 2022
    Mambo Dave likes this.
  4. Doug McC

    Doug McC Active Member

    Joined:
    Feb 15, 2022
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    Location:
    Midwest
    Vehicle:
    2022 Prius
    Model:
    XLE
    Check your owner’s manual under “If 12 volt battery is discharged” (specifically “When removing 12 volt battery terminals”) and under “Items to initialize. In the 2022 manual these are found on pages 646, 648, and 697.
     
    #4 Doug McC, Oct 31, 2022
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