Z3 Alarm Problem

Dr. Wilson · Post by **Dr. Wilson** » Wed 07 Jan, 2009 11:43

Wonder if anyone can help.

My 2.8 year 2000 zed has started to make lots of noise from about 2am in the morning. The alarm is activated for no apparent reason (not near passing diesels, thunderous roads etc) and this morning went off three times in the early hours.

I’m in danger of being lynched by my neighbours if this keeps on so I wonder if anyone can advise? I've now locked the doors using the key (as opposed to the keyfob) and the indicators don’t flash so I'm assuming the car is locked but the alarm is not active now. Am I correct in thinking this? Previous posts searched at 6am this morning seem to say both yes and no!

Will check the sensors this weekend but basically I'd like to keep the car locked but not alarmed until I can sort it.

Any help or advice is appreciated.

Post by **Robert T** » Wed 07 Jan, 2009 13:05

You have the alarm with the buttons on the key, same as me, rather than the separate fob type, so hopefully the following will be of some use.

If you lock the car with the key, the alarm will not be set - but the immobiliser will still be working - so your car is at least secure.

Now onto being a bit of relief for your neighbours... I would guess that it is either the bonnet switch or stereo anti-theft switch (particularly if you have an after-market stereo) which is causing the problem as these are the most common issues with this alarm. However it could be water in the left-hand boot-well causing problems with the tilt switch. You can also check it isn't the interior sensors by "double-locking" the car.

If you have no joy with unplugging things then the good news is that this type of alarm does record which sensor trips it and BMW can give you a printout of the codes. I had them do this with mine when it was in for service and it said both boot and interior - turned out that after I had moved the centre console I had dislodged a label near the interior sensors - the label eventually fell out all was well again!

Cheers R.

Dr. Wilson · Post by **Dr. Wilson** » Wed 07 Jan, 2009 14:44

Thanks Robert, thats really good info.

First off I'm glad to hear my girl is at least secure. Next up I'll investigate the sensors you spoke of. Did try and take a look at the bonnet one and rear arch one this morning but it was dark and cold so gave up after about 2 minutes. Dont have an after market stereo so I'm hoping I can rule that area out.

Failing all that I'll get it off to my nearest service centre and get BMW to identify which ones are tripping. Due for a service soon anyway.

Thanks again.
D

SpunkyM · Post by **SpunkyM** » Wed 07 Jan, 2009 16:16

Great reply Rob.

Zed_Steve · Post by **Zed_Steve** » Wed 07 Jan, 2009 17:43

When my alarm kept going off the problem was sourced to the tamper proof switch on the stereo. The Zed was in for a service at BMW so whilst it was there they plugged it in to the diagnostics machine overnight.

John Boy Senior · Post by **John Boy Senior** » Fri 09 Jan, 2009 10:11

I had a similar problem earlier this year, usually during wet weather. The route of the problem was the bonnet switch. A good dose of WD 40 proved to be the end of the problem. Mind you it did take a few days of trial and error to find. My advice start with the simple bits first.

Hope you sort it soon
John

Dr. Wilson · Post by **Dr. Wilson** » Fri 09 Jan, 2009 13:11

Excellent; will do and thanks all. Was a REALLy cold night so am thinking the cold probably also constricted battery power slightly and maybe didnt help. Will start simple and work my way around

raffee · Post by **raffee** » Fri 20 Feb, 2009 18:03

i have random alarm problems. i have taken it to dealer who checked codes but it has not been reset since 2007 so it was not very conclusive. they checked the tilt sensor to ensure its dry. which it is.
therefore its time to look else where.
1stly how do i double lock it, to turn off the interior sensors? so i can check them.
the stereo is standard but i did take it out a week ago and put it back in. the alarm issue has been happening over the last 3days. could i have upset the sensor there? if so how do i check it. where exactly is the sensor?
any other help would be very good.
many thanks ash.

ribs · Post by **ribs** » Fri 20 Feb, 2009 19:58

Hey Rob,.. I have the same random 3.00am alarm problem on the little red roadster too. What did you mean by testing the interior sensors by double locking the car? By interior sensors are these the ones that look into the footwells and set of the alarm if they see legs or whatever moving?

Reading the manual (see below) double locking should disable 'internal' and tilt sensors.
My alarm still goes off when I do this..... so in my case it has to be the bonnet or radio sensor!!??? yes?

... taken from 2000 Owners Handbook - English IX/00 ...

Post by **Robert T** » Fri 20 Feb, 2009 20:08

ribs wrote:Hey Rob,.. I have the same random 3.00am alarm problem on the little red roadster too. What did you mean by testing the interior sensors by double locking the car? By interior sensors are these the ones that look into the footwells and set of the alarm if they see legs or whatever moving?

Reading the manual (see below) double locking should disable 'internal' and tilt sensors.
My alarm still goes off when I do this..... so in my case it has to be the bonnet or radio sensor!!??? yes?

Hi Ribs,

I would do a deliberate test - leave the window open - double-lock the car and put your arm through the window - if the alarm doesn't go off, you have correctly disabled the interior sensors and tilt switch. Now if you do the same with the window closed and leave the car and the alarm goes off it has to be something other than the interior sensors or tilt switch.

That then leaves only the door switches, boot switch, bonnet switch and stereo switch. You can disconnect the bonnet switch and check the door and boot switches by opening the doors/boot (afaik the same switch operates the interior light/boot light).

The stereo switch is harder to get at - I remember a good piccy of it on here recently, but can't find it at the min - it should be possible to disconnect that switch in some way, or at least hold it open/closed with a cable tie if you don't have the requisite prong on the back of your stereo - I swapped mine off the old headunit.

HTH.

Cheers R.

ribs · Post by **ribs** » Fri 20 Feb, 2009 20:23

Thanks Rob.... so nice to talk to someone on here who makes sense

.... off to do some testing, I'll report back later, maybe tomorrow if I get as far as the radio sensor.

Post by **Robert T** » Fri 20 Feb, 2009 20:23

Found the thread with the pics.

<img src="http://www.zroadster.net/forum/files/car_002.jpg">

Good luck ribs.

Cheers R.

raffee · Post by **raffee** » Sun 22 Feb, 2009 08:03

Ok. Thought I had cured it but NOOO!!
Went to main dealer who reset codes as there were 67 since 2007.
I have disconnected the stereo sensor, bonnet switch and had main dealer check tilt sensor! My neighbours going mad now. Went off at 2 am this morning.
Next to try is double locking to de activate tilt sensors.
Could the battery be low??
When I am driving and put something on like heater the lights dim slightly for a second then resume. Could this be a sign of battery low??
Thanks Ash.

ribs · Post by **ribs** » Sun 22 Feb, 2009 11:35

OK... I think my alarm problems are solved, story so far..

1/ Alarm goes off what seems like randamly, always when parked up and mostly during the night (temperature change??)

2/ Tried double locking so to disable interior and tilt sensors.. alarm still trips. So interior and tilt sensors OK.

3/ Noticed that tell-tail flashed rapidly for about 10 secs and thin settled down to a slow flash when alarm was armed. This is what happens when you double lock too. Checking the manual I think it says that this means that there is a problem with an alarm component but the alarm is still set (page 38 of the 2000 manual).

4/ Disconnected bonnet switch. Tell-tail still flashed rapidly for 10 secs... probably not this then.

5/ Removed radio (after market Alpine fitted by me, preiously OEM) and looked at radio contact. I was surprised to see a cable-tie on the switch, see pic below.

I wonder whether the car had had a non OEM radio fitted in the past and the switch was cable-tied in an effort to bypass it. Maybe the cable-tie has worked loose over time and now a drop in temperature results in the cable-tie releasing the contacts.

6/ Disconnected radio contact plug (not easy!!) and re-instated bonnect contact. Now when I lock the car the tell-tail does not flash rapidy but goes straight to a steady flash

I think this was my problem.... but if not, watch this space.

Z3 Alarm Problem

Z3 Alarm Problem

Bonnet Switch