Dont be Alarmed..but im having alarm problems!

[chris1984_99_99]

Hi guys, had a look through the forum there for any info on this but couldnt really find anything. Ive had the car a few years, and just now she seems to have developed an annoying habbit of going off by herself for no aparent reason! From what I can gather this can be a common problem, but its a new one to me! She'd go off by herself maybe after a few hours or minutes of being locked, it appears to be very random, but ultimately it means im afraid to leave the car locked at night incase it goes off again!

Problem is, ive literally in the last few days just moved to Abingdon near Oxford in England and I havnt a clue where to go to have this looked at! Any suggestions on first what the problem could be and maybe where I could go?

Thanks a million guys!

[BladeRunner919]

Likely culprit is bonnet switch. Easiest way to check is just to unplug it and see if the fault goes away. I have mine permanently unplugged.

[LookinFoolish]

Same problem here if i use the central locking keyfob. I was told to look at the bonnet switch but i'm not sure exactly what to look at and do with it, so i use the key to manually lock the doors - which doesn't arm the alarm, but keeps the doors locked

[wildeboy]

I have got some self adhesive pads, the type you use to protect hard floors from furniture legs, stuck to the underside of the bonnet where it meets the alarm switch to make sure it it pushed down far enough. Not very high tech but it does work (until one falls off and it starts again! ).

[zibomb]

Perfect I am having this problem and have silenced the alarm so will have a look at the switch. Thanks.

just moved to Abingdon near Oxford in England

Thats where I got my z from. Your not too far from me I'm the other side oxford near bicester

[**Z3**]

Hi

I have just had the exact same problem, left the Z and the alarm would go off randomly, sometimes within two minutes of leaving it, sometimes in the middle of the night!

I had BMW take a look at it, in deed as per other comments it was the bonnet switch which was replaced.

If it helps i was advised of the following to switch the alarm sensors off - when locking the car with your remote key fob, press the button twice in quick successes ion. This switches off the sensors both on the inside and the outside. Please note I'm not a mechanic and just repeating what BMW advised me, it worked for me!

The difficulty is establishing if you have a fault with the external or internal sensor, when they hitched my Z to the computer my bonnet sensor had gone off 33 times, but my internal sensor had gone off three times! Not sure how you can establish for sure what the problem is without the computer, but hope this helps a little?

[BladeRunner919]

The bonnet switch is easy to disable. When you open the bonnet it's a pop-up plunger switch on the slam panel, on the right (as you stand looking at the car - on the left if you are siting in the car). There's a multi-plug that goes into it. Just unplug it and leave it.

I have taken my switch apart to try and fix it, and it's just a pretty rubbish design that is subject to corrosion and pitting of the electrical contacts. I cleaned mine up and it worked for a bit, then the alarm started going off randomly again so I just unplugged it, and it's been fine since.

[chris1984_99_99]

Hi Guys, Happy new year to everyone! I hope Santa was good to you all!

The new year and Christmas period seems to have been an issue for the Z3, it seems the alarm is playing up again only thing this time even worse!

Before the alarm would go off randomly and would stop when I went out and pressed the key fob. Since then ive been able to lock the car and by pressing the key fob twice to deactive the alarm, it seems to have been ok. Until, the other night when it started to go off by its own. I went out, pressed the key fob to unlock the car, and it made no difference! I got into the car, turned on the ignition and still the alarm was going!

Not looking suspicious at all, I drove the car away from all the houses and took it to a quiet car park to try and figure it out, all the while the alarm was still sounding! Eventually it stopped, but as soon as I would press the key fob, it would go off again and take a long time to stop. So now, it appears I cannot lock the car without the alarm sounding!

I had a look on here that very night and looked up this old thread and saw someone mentioned about checking the tilt sensor in the back left of the boot under the trim. I had a look in there and low and behold, there was water! Also the interior boot light and light inside the main cab no longer seems to be working. Is it maybe a case of a fuse that has gone due to the water? Im trying to dry the car out the best I can, but the weather here recently hasnt been great for that. Does anyone have any ideas or suggestions? Is it a case of drying the car out and replacing a fuse and cross some fingers?

Thanks in advance guys!
Chris

[BladeRunner919]

Are you sure it's not a bad fob battery, or a dodgy fob?

I don't think (I could be wrong) that the alarm going off would prevent you starting the car, as the immobilisation is separate to the alarm and works off a transponder in the key. So I don't think you should be distracted by the fact that you can start the car with the alarm sounding, just stick to the issue with the alarm itself.

[Fender2004]

When my bonnet switch for the alarm was not working I got an extra beep from the car when the alarm was set.
I also got a pad to push the bonnet switch further in and touch wood I've had no more bother