Alarm Going Off Spontaneously

[Roentgen]

My 2006 250 SEL was parked on the drive last night and locked at 18.00. At 03.00 the alarm started! Nobody was around and the security lights only came on when I went to investigate. The reomote turned it of. I got into the car started it, moved it forwads/backwards and the parked it and locked the door- having checked that bonnet/boot/doors were shut. I went back to bed and the smae thing happened 20 minutes later;it was a calm night and we live along a very quiet country lane. Did the same manouver and went back to bed only to be woked 30 minutes later. This time I turned the alarm off with the key and left the doors unlocked! I managed thereafter to get some sleep.

Any ideas?

[Dylan69]

The first thing i would check is that the rubber is not starting to wear on the bonnet switch, Try adjusting it up a bit (a big percentage of false alarms are bonnet switches) , ALSO be very carefull about switching your alarm off, Many thieves (especially in secluded area's) set alarms off hopeing that you do just that (turn the alarm off)Probably was not in your case but you never know as if you left nothing of value in the car they would have checked it and left. Just a thought.

[beneee]

I am having exactly the same issues, see "Christmassy Dashboard" post!

My car alarm started going off randomly a few days ago, i can't wait till i drop it off at lexus for them to sort ALL the problems out

I am currently locking the car manually using the key under the plastic flap as that seems to lock the car without activating the alarm, well it has not gone off since i started doing it.

Ben

[rob_clio172]

i would put money on it being a faulty intrusion sensor :winky: , its located next to the front interior light

[Roentgen]

I did as Ben suggested, locked the door manually. 24hrs later all is ok. The garage suggested, like Rob, the possiblity of problems with the internal ultrasonic sensor. The latter 'can be tripped off by flies or spiders!'. If the problem recurs I will isolate it - instuctions are somewhere in the manual.

Ben -I will now read the "Christmassy Dashboard" post. Thanks

Martin

[adjust8r]

I had the same problem with my 08 220d se. A tiny fly got into my car and set the alarm off about 3 times one evening!!! I had to leave the car unlocked with alarm off and next day, when I opened the car, the little fly departed. Never had a problem since.