Is that the alarm box?

[asmagal]

Thanks for your help.

Under the back seat, opposite to the battery and behind the
GM and RM modules basket, REALLY VERY HIDDEN,
I found a black box with three sockets and a fuse.
The label shows the following:

BMW 8 366 229
(xxxxxxxxxxxxxxxx bar code)
084659058 0014279 03
LOEWE HW: 18 / SW: 96 34331

What could it be?
Thanks again.

[Qsilver7]

Thanks for your help.

Under the back seat, opposite to the battery and behind the
GM and RM modules basket, REALLY VERY HIDDEN,
I found a black box with three sockets and a fuse.
The label shows the following:

BMW (part # 8 366 229)
(xxxxxxxxxxxxxxxx bar code)
084659058 0014279 03
LOEWE HW: 18 / SW: 96 34331

What could it be?
Thanks again.
Using the online parts database (http://www.realoem.com/bmw)...when you insert the part number you gave in the "parts-cross-reference" link...it comes up as the Ultrasonic DWA Control Unit: ( http://www.realoem.com/bmw/partxref.do?part=8+366+229+&showus=on )

If you click on "Details on E34" (in the link above)...you will get expanded choices to pick the e34 you own ... and you can continue on to see an exploded diagram of the part.

So what does that mean? DWA is the acronym for the anti-theft system...in other words...its the double-locking system that will set off the alarm and depending on if you have EWS (immobilizing system)...(you didn't leave any info about which e34 you own...they are not all configured the same)...it shuts down the starter and/or ignition and fuel supply. ;)

Cars equipped with EWS...will also have an embedded chip inside the key that communicates with the car when inserted into the ignition. The car will not start (fuel/ignition/starter immobilized) without the "programmed key" for your car.

If you have the BMW/Alpine keyless entry module (see image below of it attached to the rear E-box under seat)...or a 1994-95 540i with its fat black head key w/intergrated remote fob...they too work in tandem with the DWS module in "double locking" the car and setting the alarm.

But again, depending on what year & model e34 you have...determines which , if any, of the above systems is in your car.

(will not find this unit below in a 1994-95 540i...it uses a totally different keyless entry system)
http://memimage.cardomain.net/member_images/7/web/739000-739999/739005_32_full.jpg

[asmagal]

Thanks to Qsilver7 for very helpful and instructive
information. It is the first time that I post a thread
and I feel very happy with the returned information.

As a matter of fact, my car is a 1994 european 520i.
The alarm ECU is not the Alpine but that one hidden
behind the GM and RM boxes basket. The key is the
fat one indeed. Unfortunately, neither the alarm nor
the keyless entry are working.
Thanks again.