Alarm keeps going off

[ToniJ]

My alarm kept going off so I had the Battery checked. The meter said 'replacement recommended' so I had a new one fitted, just got home and the alarm has gone off within 20 minutes!

Anyone have any ideas?

[Ian M]

The alarm on my SC went off unexpectedly while I was visiting my dad last week.  I think the muddy cat paw prints which went from the bonnet, up the windscreen and over the roof were probably to blame.  

[m4rkw]

1 hour ago, ToniJ said:

My alarm kept going off so I had the battery checked. The meter said 'replacement recommended' so I had a new one fitted, just got home and the alarm has gone off within 20 minutes!

Anyone have any ideas?

Scan it for codes if you can, and check the Battery voltage. It could be a parasitic draw draining the Battery and causing the alarm to trigger. With everything off check the draw from the Battery with a multimeter.

[m4rkw]

Also on some toyota/lexus if you press the lock button on the fob twice it deactivates the motion sensors. If it keeps happening you could try that one day to test and see if it still goes off. If it doesn't then at least you know the issue is something to do with the motion sensors.

Maybe you have a fly trapped in the car? 😄

[m4rkw]

Oh actually you can test it - sit in the car and lock it with the key, press lock twice. Move around inside the car and see if the alarm goes off. Repeat without pressing it twice to verify the motion sensors work.

[WESTIE]

I have had mine go off twice. The first time was because I had left my mobile phone in the car and the second time my tablet. Both devices search for a signal and this trips the alarm.

[ToniJ]

Thank you to everyone who has replied. It is still a mystery but it hasn't gone off since yesterday (fingers crossed!). 

 

[PRT68]

I had problems with my alarm when I had a Prius. Leaving my phone inside, mirror effect sunglasses stored in the interior mirror box, and being parked in my driveway nexted to a kitchen window with a microwave oven in sight , all caused the alarm to go off.