Alarm keeps going off...

TikoV

Member
 Glasgow
Past couple of weeks once the alarm is activated within 20 mins or so it sets off and to the point where I just unlock the car. Luckily the car is surrounded by the X5 and M5, so I know it can't go walkies. It's just when I do take it out, without fail on my return the lights are flashing informing me.

Is this due to a drop in voltage in battery or some underlying problem. Will get battery checked.

Anyone else suffer similar symptoms?

Thanks
 
sure somebody will come along with a proper answere, but if i was to have this problem i would look to see it the bonnet switch can be linked out temporarily, see if that then stops the alarm going off
 
Yeah, as Taz says, sounds like the bonnet switch. Just unplug it and see if the alarm problem disappears. Replacements are around a tenner from Sopers.
 
markeg said:
Yeah, as Taz says, sounds like the bonnet switch. Just unplug it and see if the alarm problem disappears. Replacements are around a tenner from Sopers.

Yup, simple test as they say is to unplug it - this is what made me join the forum as had exactly this issue
 
stevecbrz4 said:
Has anyone got a visual illustration to show where this bonnet sensor is and how to unplug it? Thank you.


Its central down the engine bay directly between wipers & is a push contact that the bonnet sits down on .
Hard to miss when you know where it is :oops:
 
If you lock the car using the key it locks the doors but does not arm the alarm on mine. At least its more secure
Bonnet or anti jack sensor as previous :wink:
 
I had a similar problem with my 04. Others suggested the bonnet switch so I tried to test it with a multimeter but ended up just disconnecting the switch and leaving it un-plugged for a couple of days and the problem went away. I ordered a new switch through Sopers for £9.98 including delivery and once fitted (in ten mins tops) I've not had any problems since.

I did some scouting around on the internet and located a interesting background reading document - available here (https://www.bavauto.com/Assets/inst_pages/ins229.pdf‎) - this shows quite clearly the switch position and has info about other alarm sensors.

Good luck.
 
You need to get it coded to check what is causing the fault, bonnet sensor is a favourite but could be the tilt sensor. If its the later you can deactivate this via coding. Try disconnecting the bonnet sensor and set the alarm if it still goes off then you know it's not that.
 
mac27040 said:
You need to get it coded to check what is causing the fault, bonnet sensor is a favourite but could be the tilt sensor. If its the later you can deactivate this via coding.

Or a double push of the lock button on the remote disables the tilt.
 
Many thanks for the reply peeps..

Thing is it's very intermittent when it decides to go off. Not had a minute to check bonnet sensor but hoping this is the culprit.
 
TikoV said:
Many thanks for the reply peeps..

Thing is it's very intermittent when it decides to go off. Not had a minute to check bonnet sensor but hoping this is the culprit.

Mine was the tilt sensor as it normally did it when windy......double click the lock button on the key to disable.
 
These sensors are a PITA, mine kept playing up in my Series 1, would often tell me my bonnet wasn't closed and then the alarm would go off, lights flash. Ended up running my battery down on two occasions. I disconnected it and havn't had a problem since.
 
Mine kept going off so I disconnected the bonnet (hood) switch. This made no difference. So, I had a tech check the alarm. It has a faulty "brain," which would costs hundreds of dollars to replace. I didn't want BMW's Sh**** alarm in the first place, but Viper's local authorized installer gave up after 2 days of trying to install their alarm in my car. They said it couldn't be done, so I had to pay the same price for BMW's crappy alarm, which became defective 14 months later. I will not give BMW another penny for their crappy alarm system. Once again, I love my car but I HATE BMW.

I hope your issue is just the bonnet switch. That's a bit of lubricant, or, if it needs to be replaced, a $15 fix.
 
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