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Prius alarm system malfunctioning

Discussion in 'Gen II Prius Care, Maintenance and Troubleshooting' started by desperatedan, May 30, 2010.

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  1. desperatedan

    desperatedan New Member

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    Location:
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    Your Vehicle Year:
    2005 Prius
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    Hi,

    In the past five years I've owned my 2005 Prius the built in alarm system has been producing lots of false alarms.

    Recently the problem has got a lot worse and the alarm went off three times on Friday, and just now waking me up and prompting me to post this thread!

    I have absolutely no idea what's causing this - some ideas include parking on an incline, not activating the emergency brake, car getting blown by wind, or failing to press the little Radar-Off button under the steering wheel. But the sad truth is that it seems totally random.

    Every time my Prius goes for a service I mention it to them and the say they will "turn down the sensistivity" (whatever that means). It never fixes the problem and they never have a clue what to do about it, merely announcing that it didn't happen to them (which I believe).

    Is there any way to rip out the awful alarm system entirely? I don't care about it anyway. Alternatively, if they are able to turn down the sensitivity, can't it be turned down to zero - or am I being fed nonsense here and there is no sensitivity to adjust?

    Please help, I'm at my wits' end on this one and it's driving me and my neighbors crazy...

    Thanks
    dd
  2. vertex

    vertex Active Member

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    Location:
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    Your Vehicle Year:
    2006 Prius
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    How old is your 12 volt battery? Have you tested it lately?
    1 person likes this.
  3. vertex

    vertex Active Member

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    Also, there is a seperate theft deterent horn under the hood to the right of the windwshield washer bottle, unplug it.
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I suggest that you ask your dealer to find and disconnect the glass breakage sensor (if possible) or else find out where the sensitivity control is located, and adjust it yourself. This is an option on US cars and I do not know where to find this.

    Test by hitting the windshield fairly hard with the palm of your hand, and see if the alarm comes on (it should not). Also push down on the front and rear bumpers as hard as you can, and see if the alarm comes on. Good luck.
  5. firepa63

    firepa63 Former Prius Owner

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    Most likely the glass breakage alarm... My brother-in-law had it disconnected on his Prius because of the alarm going off for no reason. Just have the dealer deactivate it.
  6. desperatedan

    desperatedan New Member

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    Hi
    sorry to drag up this thread but I just wanted to thank those who helped me and vertex in particular who suggested it might be the battery - I replaced it (the battery) soon after the suggestions on this thread (against the protestations of the toyota engineer, i might add, who said the battery was "fine" - he soon shut up when I showed him the money!) - and I haven't had a single false alarm since.

    Result!
    thanks,
    dan
  7. vertex

    vertex Active Member

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    Glad I was able to help!
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