2005 Prius alarm randomly goes off!

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Caliveltz, Oct 2, 2016.

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  1. Caliveltz

    Caliveltz Junior Member

    Joined:
    Nov 24, 2014
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    Location:
    San Marcos, Ca
    Vehicle:
    2005 Prius
    Model:
    Three
    2005 Prius Package #3 169,000 miles
    Recently, the alarm goes off without warning. As it's going off, it will NOT respond to the key fob unlock function. It only shuts off when I physically insert the square fob into the ignition and start the car. As soon as i power down the car and remove the key, it immediately goes off again! I insert the key in the ignition again and start the car and the alarm goes silent. Then, sometimes, the lock/unlock function on the key fob works perfectly. I checked the 12v battery and it is at 12v stationary and 14.0-14.2v when car is on. Fob battery is new. Any ideas gentlemen?

    Thanks!
    James
    San Marcos, Ca
     
    #1 Caliveltz, Oct 2, 2016
  2. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,600
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    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    Disconnect the alarm. And charge your 12v battery. It should read 12.6v or higher after sitting 10 hours
     
    #2 JC91006, Oct 2, 2016
  3. dolj

    dolj Senior Member

    Joined:
    May 14, 2012
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    Location:
    Wellington, New Zealand
    Vehicle:
    2007 Prius
    Model:
    N/A
    How old is the 12 V battery?
    If is less, replace the 12 V battery. Best option is OEM Truestart AGM, pro-rated 84 month warranty.
     
    #3 dolj, Oct 5, 2016
  4. Jmack111

    Jmack111 Member

    Joined:
    Nov 3, 2009
    371
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    Location:
    Tacoma wa
    Vehicle:
    2004 Prius
    Model:
    N/A
    My problem was the horn alarm was going off randomly and the touch handle unlock sensor was no longer working the button to lock on handle works fine. was not the fobs. Started with a bad actuator. door were not locking so take apart actuator cleaned motor contacts put motor back together reassembled actuator taped actuator arm to the right position just to make my life easier underneath shalf to hold up the same direction as it goes in to the handle then use thread to hold the locking key part down and to the right while moving the actuator tilting it towards the outside of the car to get them to match back together this is when my problem started with the horn to fix it I ended up reading this post then I just unconnected the two cables coming from the lock assembly to the frequency box for two seconds without touching any metal in the car with the door closed and then reinstalling wire and the horn stopped making noise and the door handle started working thank you for the info see the pictures

    . 20190115_172720.jpeg 20190115_172545.jpeg 20190115_172441.jpeg

    Posted via the PriusChat mobile app.
     
    #4 Jmack111, Jan 15, 2019
  5. Jmack111

    Jmack111 Member

    Joined:
    Nov 3, 2009
    371
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    Location:
    Tacoma wa
    Vehicle:
    2004 Prius
    Model:
    N/A
    Turn out door Actuator was Wasn't working on one door but if you manually lock it the alarm Won't go off or in hook Driver side sensor with Caron and plug back in that will last 30 days but real fix it to clean motor in Actuator or replace it spray switch with cleaner. Back one harder the front.

    Posted via the PriusChat mobile app.
     
    #5 Jmack111, Jun 26, 2019
  6. Jmack111

    Jmack111 Member

    Joined:
    Nov 3, 2009
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    Location:
    Tacoma wa
    Vehicle:
    2004 Prius
    Model:
    N/A
    Did it again turn out to be drivers door Actuator tried motor in it first worked but alarm still there only a mirco swich in there left swapped whole unit with the 12v battery un hooked

    Posted via the PriusChat mobile app.
     
    #6 Jmack111, Aug 14, 2020
  7. Jmack111

    Jmack111 Member

    Joined:
    Nov 3, 2009
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    Location:
    Tacoma wa
    Vehicle:
    2004 Prius
    Model:
    N/A
    Door actuator there a switch inside randomly works or not works and alarm goes off
    Replace driver actuator
    Work around lock by hand don't use power locks

    Posted via the PriusChat mobile app.
     
    #7 Jmack111, Sep 12, 2020
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