Alarming when starting

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Bill5818, Dec 19, 2025 at 4:49 PM.

  1. Bill5818

    Bill5818 New Member

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    Vehicle:
    2012 Prius
    Model:
    Three
    I have a 2012 Prius, with key fobs and push button start. Recently my horn has been sounding 3 time every time I start it. It starts immediately and the moment I press the start button, it there are three rapid beeps. This behavior is the same if I have the fob actually touching the button also. I can use either fob and the results are the same. I have changed my fob batteries twice, with different brands of batteries, and still no change. I'm up for any suggestions you might have.
     
    #1 Bill5818, Dec 19, 2025 at 4:49 PM
  2. bisco

    bisco cookie crumbler

    Joined:
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    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
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    Plug-in Base
    no idea, but it wouldn't hurt to get a free 12v load test at many auto parts stores. for that matter, try disconnecting the 12v neg for a minute to reset everything
     
    #2 bisco, Dec 19, 2025 at 9:13 PM
  3. Mendel Leisk

    Mendel Leisk MMX GEN III

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    Location:
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    Vehicle:
    2010 Prius
    Model:
    Touring
    I tried googling:

    what does 3 honks mean, when starting a 3rd gen prius

    and the AI summary has some ideas. There's mention of possible aftermarket security system malfunctioning, for example.

    How long have you had it?
     
    #3 Mendel Leisk, Dec 20, 2025 at 12:23 PM
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