Alarm/Immobiliser Trouble E 34

[pandobair]

I have a 1994 530iA in South Africa. I have established that the alarm was factory fitted and not retro fitted. I have changed the cars battery recently and I have noticed that when pressing the unlock button on the remote the doors unlock and then re lock immediately. On the second attempt the doors stay unlocked. I have now had two occasions where I couldn't start the car (immobiliser perhaps???) The engine would turn over but I suspect no spark and no fuel? Roughly 5 or 10 mins after I lock the car the alarm goes off for no reason. Is there a way to reset the alarm and immobiliser? Please help me out with any relevant info on where to find the alarm systems components, and how to fix the problem.

[shogun]

The doorlock problem is not related to the alarm system. That is simply a problem of one of the microswitches or another problem in the locking system of the doors or the trunk lock.
See here under body, doorlock etc
http://bmwe32.masscom.net/
The system is , that the GM reacts, as a signal is missing that all doors and trunk are unlocked, so it locks again.
You can also try resynchronizing the locks. See owners manual.

The problem with the no start: you sais you changed the battery. Was there a small microswitch on top of the battery? If so, maybe this one is not correctly installed. It is part of the drive away protection system.

[pandobair]

I saw the microswitch on the battery, but wasn't sure what it was for. Any Idea why the alarm would go off for no reason after I locked the car?

[acidfire52]

If one of the switches on the door was not working quite right, after you lock it it would see a door open and go off.

[pandobair]

Very frustrating indeed! Can anyone shed some light on the battery microswitch and how it works relative to the car not starting? That pesky microswitch may well have been the cause of my headaches. If it happens again is there a simple or quick way to override the system? It didn't reset despite my leaving the battery disconnected for a while then reconnecting it.
Is there any way of determining which door switch could be faulty apart from a process of elimination?

[pandobair]

The doorlock problem is not related to the alarm system. That is simply a problem of one of the microswitches or another problem in the locking system of the doors or the trunk lock.
See here under body, doorlock etc
http://bmwe32.masscom.net/
The system is , that the GM reacts, as a signal is missing that all doors and trunk are unlocked, so it locks again.
You can also try resynchronizing the locks. See owners manual.

The problem with the no start: you sais you changed the battery. Was there a small microswitch on top of the battery? If so, maybe this one is not correctly installed. It is part of the drive away protection system.

previously the GM would react opposing signals (e.g. an unlock signal while trying to lock, as with a defective microswitch) by carrying out the first command (e.g. locking, followed immediately by unlocking). Repeating the first command then results in carrying out the command, e.g. try to lock again, and locking is now carried out. This function (Asynchronious Position)is omitted in the NEW GM.
-After unlocking is performed due to crash sensor activiation, the locking command is now reactivated by double-locking with the key from either side (driver or passenger door).

I was reading another one of your posts and I omitted to mention that I have also changed the GM module and Relay Module. My GM module was green and the one I have bought secondhand is black. Could this have something to do with my unlocking and locking problem?

[shogun]

Yes, that could be the case, probably the one you have now installed is an older one.
The later GM versions did not have that function anymore.

The microswitch should look like # 3
http://www.realoem.com/bmw/showparts...75&hg=61&fg=35

I assume if you just put a tape on it so that it always has contact, that might solve the problem.
There are many of these switches on the car, for example under the hood.

[pandobair]

Thanks Shogun you are a Wizard. I guess I will have to try get another GM card I assume there is no other way around the problem? Would changing the card to a newer one also stop the alarm persistently activating whenever the car is locked?(Takes about 10 mins to activate and horn sounds) The switch is the same as in the picture so I have taped it down!

Yes, that could be the case, probably the one you have now installed is an older one.
The later GM versions did not have that function anymore.

The microswitch should look like # 3
http://www.realoem.com/bmw/showparts...75&hg=61&fg=35

I assume if you just put a tape on it so that it always has contact, that might solve the problem.
There are many of these switches on the car, for example under the hood.

[shogun]

That will not help. You have to get rid of the complete alarm system.
I hope it is only one. I once worked for days on a car which did not start, finally turned out that in addition to the standard one it had an aftermarket system also installed, the owner had no idea off.

[pandobair]

That will not help. You have to get rid of the complete alarm system.
I hope it is only one. I once worked for days on a car which did not start, finally turned out that in addition to the standard one it had an aftermarket system also installed, the owner had no idea off.

How do I go about that daunting task. When you say it wont work do you mean taping the microswitch or changing the gm card?