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Alarm problem randomly going off

Discussion in 'Gen 2 Prius Main Forum' started by gd420mj, Sep 29, 2016.

  1. gd420mj

    gd420mj Junior Member

    Joined:
    Aug 18, 2011
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    Location:
    RTP, NC
    Vehicle:
    2006 Prius
    Model:
    N/A
    What A Night! Thought I share what I found, read many old threads on problem.
    Have an '06 with about 230K miles. Everything stock. I don't know if I have glass break sensor, but not that anyway.
    Last night at about 12:30 am, my alarm goes off. I shut it off with FOB through window. Freaked out that someone is outside, I fall back to sleep. about 1am, it goes off again. Except this time, I can;t stop it with FOB. I run out in the RAIN all the while pressing the FOB at the car and still can't stop it. I insert key in dash and start car to stop alarm. I kept some doors unlocked and didn't arm it. Well it goes off Again. While in car thinking what to do so I don't wake the neighborhood, it goes off AGAIN (while car is off and fob is inside car).
    I pull the Horn Fuse and Theft Deterent Fuse hoping that'll at least give me quiet till the morning. Back to bed with car unlocked. It goes off AGAIN at about 3 AM. The horn sounded too, but was a quieter horn. (10A fuse pulled under hood).
    Through all this, I did notice fob would sometimes not arm/disarm car. So at 3:30 am, down to 24 store to replace FOB battery. Hey, it even did it store lot after I shut car off and was taking battery out. I noticed as I was in store, no battery in fob, it didn't happen.
    New battery in FOB and has not happened again. SO, I suspect the FOB was acting up. Also, I am missing the Red button for panic and switch is exposed. I read others maybe had issues with switch contacts, etc.

    I first thought the 12V battery, and while its probably lower than everyone thinks is OK, it still functions fine. with over 220K miles, I'm only on 12V battery #2, that I actually bought USED on craigslist for $20 and has gotten me through about last 2 yrs.

    Our cats like to lounge on top of our cars, and never in the 5 yrs I've owned this car, has the alarm ever randomly gone off.

    If alarm in UNARMED, Suspect problems with FOB. As alarm shouldn't activate if UNARMED, but panic button will activate if UNARMED.
    New FOB Battery may not always fix. PCB problems, corrosion, etc could all affect FOB and most wouldn't know.
     
    'LectroFuel likes this.
  2. kenoarto

    kenoarto Senior Member

    Joined:
    Feb 7, 2006
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    Location:
    Chicago, IL
    Vehicle:
    2005 Prius
    Model:
    II
    Whatever you do, be sure not to fix your known problems. Don't replace the broken FOB. Don't replace the FOB battery. And don't replace the 12v battery you got for $20.