ALARM PROBLEM

[maverick25]

Hello All,

After lurking on here for a while reading up all there is about the z4 I have finally bought a lovely black, 2005 3.0i litre, with just 18,000 miles. I am absolutely loving it!

The only problem I have at the moment is that the alarm, when set through the key fob, goes off for no apparent reason. This can either be 20 seconds, a few minutes or several hours after the alarm is set. When I lock the car manually the alarm seems to be fine (although I'm not sure if this activates the alarm?).

I only bought it off the independent dealer a few weeks back but I'm pretty sure this wont be covered under the standard 3 month dealer warranty.

I'm reluctant to take it to a BMW dealership just yet as it may be an easy fix and it's one of those problems that when I take it to the dealer the alarm probably won't go off, they will charge me 2 hours labour and when I get it home the alarm will go off again!

Any advice hugely appreciated.

C.

[WLH]

maverick25, welcome to the forum...
I have no idea what the cause of your problem is...
I have the BMW dealer installed alarm system and when I lock using the key the alarm is not active.

[gannet]

welcome to the forum

bonnet sensor is common failing...

[maverick25]

....where is the bonnet sensor? Will it need replacing and is it something I could do?

[Zedster]

As Gannet has already said and there are a number of threads on here indicating to a possible Bonnect Sensor fault.

i would take the car back to the Dealer and complain that the fault was on the car when you bought it. Get them to fix.

[RustyZ4]

As Gannet has already said and there are a number of threads on here indicating to a possible Bonnect Sensor fault.

i would take the car back to the Dealer and complain that the fault was on the car when you bought it. Get them to fix.

x2

Hi & Welcome btw

[Nick_in_Suffolk]

My wife's car suffered a similar problem; the alarm would trigger at random intervals after setting. Locking the car manually does not set the alarm, so was an acceptable short term solution.

It was the bonnet closed sensor; about £10 from BMW and a complete doddle to fit.

[maverick25]

Brilliant! Thanks chaps, I will give it a go.

[Oldfella]

Hello folks,
I had the same problem with my alarm, Googled it, found this forum, and promptly bought the bonnet switch, for £8. It solved the problem. Given that the BMW dealer had a few of these switches in stock, I guess it is a common problem!Thanks for the advice.

[IvanDobskey]

I seem to have this problem with mine! Alarm keeps going off. Anyone know where abouts the bonnet sensor is? I'll give it a go changing it.

[easty027]

as above, i bought a bonnet sensor for £8 from my local bmw stealership and swapped it over in a matter of seconds. And im no specialist !

[IvanDobskey]

Is it obvious where under the bonnet it is? I've only just bought the car and I've got both the wiper and alarm problems. Very annoying!

[gannet]

it is under the windscreen in the middle - where the two diagonal strut braces meet at the centre of the car

pretty obvious when in front of you

[IvanDobskey]

Ah ok, cheers! I've got a few bits and pieces I want to pick up from my local BMW dealer anyway so I'll add a bonnet sensor to the list.

[chris]

Mine had this too, took about 30 seconds to fit

Stupid putting it right above the engine, all the heats going to kill it!