Alarm gone crazy!!!

Rialas

Active member
Hi everyone.

Just got back home after being out most of the day to find the car alarm going off LOUD. Spoke to the neighbours and apparently it's been doing this most of the day.

It's been playing up this week primarily when I start the car, it goes off for about 10 seconds and using the remote to lock/unlock the car makes no difference.

Sounds as though the siren is in one of the rear wheel arches but hard to to tell whether o/s or n/s as its such a loud screech. Also where would the alarm module be located.

Ps disconnected the bonnet switch a few days ago so this is definitely not the problem.

I disconnected the battery and the noise turned intermittent. Reconnected, clicked the fob and disconnected again and now it's stopped. I'll leave it for tonight and explore further tomorrow.

Any help appreciated

Thanks.
 
The siren is behind the right rear wheel. There is no separate control module. Most of the control is part of the general module, the remainder is part of the siren. You might check the tailgate sensor as well. In the lid just above the latch.
 
bcworkz said:
The siren is behind the right rear wheel. There is no separate control module. Most of the control is part of the general module, the remainder is part of the siren. You might check the tailgate sensor as well. In the lid just above the latch.

Thank you.
I'll have a good search tomorrow. Ps mine is the M and after searching, it may be under the car between the two exhaust boxes?

What is the "general module" and could this be where the fault is? Sounds scary if it's part of the car's main brain.

Didn't realise there was a tailgate sensor and will look at this as well.

Thanks again.
 
it's more than likely your bonnet sensor, sits under bonnet where the strut braces meet in the middle on the rear wall.
Common fault on these cars, disconnect it and it'll stop. mines been disconnected for a year now.
 
th30d0r3 said:
it's more than likely your bonnet sensor, sits under bonnet where the strut braces meet in the middle on the rear wall.
Common fault on these cars, disconnect it and it'll stop. mines been disconnected for a year now.
he's already tried that...
 
I disconnected my bonnet switch too and it carried on for a few days, then I fitted a new bonnet switch and it stopped.. So maybe it does like the fact its not getting an input from the bonnet or moisture is playing with the disconnected end.
 
Thanks everyone. I'll try replacing the bonnet switch in case but I think my symptoms are slightly different. It's mainly happened when turning on the ignition or starting the car.

Another member has started a thread re how to work out which trigger caused the alarm. I'll read the manual to see if it's any of the motion sensors. The MC doesn't have a tilt sensor on the siren (or is that just us spec cars).

Can anyone tell me where the bootlid switch is. Can't see it...on the lock mechanism?

Thanks.
 
Rialas said:
Thanks everyone. I'll try replacing the bonnet switch in case but I think my symptoms are slightly different. It's mainly happened when turning on the ignition or starting the car.

Another member has started a thread re how to work out which trigger caused the alarm. I'll read the manual to see if it's any of the motion sensors. The MC doesn't have a tilt sensor on the siren (or is that just us spec cars).

Can anyone tell me where the bootlid switch is. Can't see it...on the lock mechanism?

Thanks.

Does the engine start? maybe the immobilizer?

Maybe is part of the trucklid lock part 1 as it has a microswitch:
http://www.realoem.com/bmw/showparts.do?model=DU92&mospid=49422&btnr=41_1709&hg=41&fg=60
 
aquazi said:
Rialas said:
Thanks everyone. I'll try replacing the bonnet switch in case but I think my symptoms are slightly different. It's mainly happened when turning on the ignition or starting the car.

Another member has started a thread re how to work out which trigger caused the alarm. I'll read the manual to see if it's any of the motion sensors. The MC doesn't have a tilt sensor on the siren (or is that just us spec cars).

Can anyone tell me where the bootlid switch is. Can't see it...on the lock mechanism?

Thanks.

Does the engine start? maybe the immobilizer?

Maybe is part of the trucklid lock part 1 as it has a microswitch:
http://www.realoem.com/bmw/showparts.do?model=DU92&mospid=49422&btnr=41_1709&hg=41&fg=60
Thanks. I guess the whole lock would need to be replaced. I'll check to see if there's a wire/plug connected to it.
 
All I could find on tailgate sensor is this:
GREO_E86_61_0001.png

It's S167a, does look like it may be part of the latch.
The WDS reference I used at spaghetticoder.org doesn't show a difference for M siren location, but that doesn't mean it's the same.

General module is a major brain component. It controls central locking, interior lighting and a slew of other things. On LHD cars it's a white box attached to the inside of the kick panel below/forward of the glove box, so on RHD it'll be on the panel above the pedals? Surely someone in all the drive on left countries has seen this and can confirm? I'd be reluctant to suspect the general module unless there's other related issues, like balky central locking. Wouldn't hurt to check the connectors though.
 
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