Z3 alarm tilt sensor, motion sensor, sounder

[tazmantic]

Hi all and sorry if the answer is in here I've searched to no avail, the quick question is will the interior motion sensor (believe mines the microwave units) still work with the tilt sensor in the boot removed???

Now the story, some time ago now I found the tilt sensor under water (like they do) well I removed, dried and refitted but never tested I also noticed that the alarm sounder was also not working but as there were other issues else where with the car I didn't investigate further. Today I decided to have a check and found that the tilt sensor did not set the alarm off (bonnet, boot, doors all do but no sounder) I also discovered that the motion sensors in the car also didn't set the alarm off.

I discovered that the power cable to the tilt sensor was corroded in the plug and broken so re soldered this but still no joy, with the tilt sensor connected or disconnected the motion sensors in the car don't set the alarm off (fuses in main fuse box all ok)

I know the motion sensors in car and tilt sensor are connected together so wondering if they both have to be ok for any of them to work. I know if you double press the key fog it turns these sensors off but I'm not doing this.

Thanks

[Muzz258]

Its been a while since I have worked on the alarm system. My 2.0L Z3 is from the UK and has both the tilt and motion sensors. I remember that the motion sensor took a few minutes to become active once the alarm was set. Are you giving it some time to settle down before testing its operation?

Looking at the wiring diagrams for the anti-theft system (DWA), two things are noticed:
- The motion sensor is not shown on the diagram. This may be due to the diagram being for the USA and the motion sensor only being a UK feature.

- Unplugging the tilt sensor will not defeat the other functions of the alarm system.

Set the alarm and watch the red led. If it flashes 10 times quickly then stops flashing, it means that one of the monitored circuits is faulty. It should continuously flash about once a second when everything is good.

With the alarm set, unlocking and opening the door will set off the alarm. This will check that the alarm is working.

I used INPA to check many of the alarm inputs when sorting out my alarm system. See link https://www.bimmerforums.com/forum/s...xperimentation

The bonnet/Hood switch is a common failure point. If you unplug it, The open circuit looks like the bonnet is closed.

If you have an after market stereo, the anti-theft switch behind the stereo is often just left in the cavity and causes problems. Again, just unplug it.

[tazmantic]

Hi muzz thanks for the reply,

I've found a diagram that shows them (hopefully attached) and after some more testing today think the tilt sensor is at fault..

It seems I was not waiting long enough for the interior sensors to work but if I disconnect the tilt sensor they don't seem to work as the output from the ZKE4 goes through it, I also discovered that the switch behind the radio was disconnected and this MUST of been done by BMW years back when they changed the radio after breaking the original one (like for like) looks like they didn't even attach the part on the back of the radio that goes into the switch (no wonder its always been a bit wonky)

Its been ages but I ran INPA to check inputs etc (best I could as couldn't remember how to use it) and there was an error

68 Pitch sensor, fuse or cable
static error

also when looking at inputs/outputs I could not find one for the interior sensors but found tilt output that was white but went black when alarm armed and tilt input that stayed white whether alarm set or not.... So I'm presuming the tilt sensor is faulty.

as for the red alarm led that flashes quite fast about 20 times when armed then slows to a gentle flash

[delvec]

You still have a fault if its flashing quickly. Did you check the hood switch? Additionally, I'm assuming the tilt sensor was working before it was under water? INPA gives you the option to turn it on or off.

[tazmantic]

here is a link to the video of the light ime sure it was always this speed but cant be sure and yes tilt worked fine till under water..

Im am a real novice with INPA so dont know how to do this

https://youtu.be/GAuHq2difHw

[Muzz258]

Well done in finding the wiring diagram. It's not one that I have.

The tilt input that stayed white weather the alarm was set or not could because the car had not been tilted. Reset the alarm and jack up the back left wheel a bit. It does not take much to set of the tilt sensor. Monitor the input with INPA and you will likely see it change state.

The fault code is saying that the tilt sensor has a problem. If its not the wiring, then a new tilt sensor may be needed.

[tazmantic]

I did tilt the tilt sensor as its not attached and no input showed so its looking like a dodgy sensor, just need to find one now ;0(

Found diagrams here http://www.gbnetwork.co.uk/bmw/downloadetm.html