Interesting car alarm phenomenon

[theonew]

I parked my 1995 525i Wagon the other day and set the alarm. I went up to my apartment and realized I had left my cell phone in the car. A minute later my car alarm goes off. I look out the window and noone is messing with my car. When I go down to get my cell phone I saw that a call had come in that corresponded with the time that the alarm went off. So today I told a friend to call me and put the phone in the car and set the alarm. Sure enough when the call came in my alarm went off. Its the stock BMW alarm that came with the car.

[Qsilver7]

if you look on the below the rear air vent...on the panel where the LED light is...there should be a small round black plastic thingy...that "thingy" is a microphone that is used to pick up glass breakage. Your phone is probably at the correct decibel to set off the glass breakage sensor. That would be my guess. :D

[theonew]

Very Interesting. That would make sense. Now I have to go try it with the ringer off just to make sure its not somehow electronically related.

[Qsilver7]

Very Interesting. That would make sense. Now I have to go try it with the ringer off just to make sure its not somehow electronically related.
You can also turn the sensitivity of the glass breakage sensor down...there's a button on the control unit (under the rear seat on the driver's side):
http://memimage.cardomain.net/member_images/7/web/739000-739999/739005_12_full.jpg

If you don't have the keyless entry instruction booklet in your glove box (in the owner's binder)...you can get more info about your keyless entry/anti-theft system on page 3 of my cardomain site: http://www.cardomain.com/ride/739005/3

[liquidtiger720]

Thats cool
Imma turn mine WAY up! lol.

[theonew]

I just tested it again, it only does it when the phone is on vibrate. Guess that makes sense, just wouldn't have thought that it would have been enough to trigger the alarm.

[StorminNorm]

I have to tackle this next. I dont remember seeing that black box alarm unit in top of that bank of wiring under the seat. My 95 540i has an alarm with the control in the key. It false alarms all the time and its not practical anymore to use it.

[Qsilver7]

I have to tackle this next. I dont remember seeing that black box alarm unit in top of that bank of wiring under the seat. My 95 540i has an alarm with the control in the key. It false alarms all the time and its not practical anymore to use it.
you won't have the control unit under the rear seat like you saw on my site. The 540i uses the newer anti-theft/security system that's also in the e38/e39. It's a totally different set up. :)

[StorminNorm]

you won't have the control unit under the rear seat like you saw on my site. The 540i uses the newer anti-theft/security system that's also in the e38/e39. It's a totally different set up. :)


They must have hid it cause I cant find the damn thing.

I was going to have the stealer or a shop fix it but I only have 1 key with a remote. I am tempted to just shell out the $250 for a nice Clifford that my friend installs.

[Jose]

Your problems sucks man. I know all about it. My previous car reacted to also on phone frequencies, it even triggerd the remote start option once. After that I installed a new simpler alarm. Never had problems afterwards.