Central locking problem (will not unlock)

[Ken35i]

Hi guys,

A couple of days ago I went to unlock my car from the driver side (as you normally would). I heard a clunk but the doors didn't unlock, I tried again and then the doors unlocked. I didn't think much of it. After shopping (with car locked) I went to unlock the car again and I heard the clunk again but the car was still locked. I tried again and it would not unlock (no clunk noise this time). I kept trying but it wouldn't unlock, even from the passengers side and the boot (trunk) though the boot unlocked. I let it sit for a while then tried again and after some attempts it opened. I noticed when the locks clunked but didn't pop up that its like they tried to pop up but didn't have enough power...

Anyway, I'm here today and the doors will not unlock. I have unlocked the passengers side door by lifting the handle and turning the key beyond the 'unlock' position. But I cannot pull up any of the buttons. From some searching I've done it's common that something else fails, windows, wipers for example. But everything else works. Could it be one of the micro-switches in the doors? the General module? I can only open the passenger-front door. If there's a problem with the drivers side door I can't fix it. I've unplugged the passengers side lock harness and it doesn't make a difference to the other door locks.

The ignition must stay in accessories other wise the windows will wind up. The fuses look good. I can't think of anything else to do.

Long time no post

[shogun]

What happens when you push the driver's lock down on the inside with the door open? Do the other doors lock? Does everything automatically unlock immediately again? (or possibly all the doors except the drivers unlock?)
Usually when the actuator motor fails it fails in both the lock and unlock positions.
If it won't lock or unlock from the passenger door I would suspect the actuator motor.

Shayne wrote an article about this BMW E34 door lock actuator repair


Did you check the fusible link behind battery. 80A cheapest from VW. Go to a VW dealer's parts counter or a VW parts retailer and ask for an 80A Fusible link. About $1.
If you have a local BMW dealer and insist on the BMW part ask for part number 07119978840
BMW E34 Website

In case your battery is under rear seat:
The images of/for the location and style will probably be incorrect for your car. In all likelihood yours will be under a black cover with a heavy gauge wire running to it directly behind your battery. Under the rear seat bolted with two 10mm nuts, the black cover is much like the one pictured at the shock tower.

It may also be due to a broken part inside the doorlock an overload for GM (internal reversible overload relay).
The general module = GM has an internal electronic reversible overload relay. Translate this with google which I posted on the German forum. This I posted with regards to windows and sunroof, but same applies to locking/unlocking:


Fensterheber und SHD= electric sunroof:
Es gibt da Prioritaeten wie das ablaeuft in der Beschreibung ZKE.
Das Relais schaltet ab

-wenn laenger als 60 Sekunden ein Strom von ueber 36A oder
wenn laenger als 0.3 Sekunden ein Strom zwischen 36 und 60A oder (Ueberlastung)
-wenn laenger als 0.1 Sekunden ein Strom groesser als 60A fliesst (Kurzschluss)

Um die Laststromkreise TSH/ZV/ZS/FH/SHD sicher vor Ueberlast zu schuetzen, wurde zusaetzlich zur 30A Sicherung eine elektronische (reversible) Stromsicherung eingebaut.
Im GM wird der Spannungsabfall am RM gemessen, und je nach Spannungsabfall (Stromschwelle) unterbricht das Sicherheitsrelais den Laststrom .

Die Abschaltwerte der 30A Sicherung werden dabei nicht erreicht (diese wurden nur dann schmelzen, wenn ein Defekt an der elektronischen Sicherung vorliegt).
Die Ansprechschwelle dieser elektronischen Sicherung ist so gelegt, dass immer vor Ueberlast der angeschlossenen Steuerungen automatisch abgeschaltet wird.
Ein automatisches Wiedereinschalten erfolgt nach 60 Sekunden!!!!
Jedoch nur dann, wenn diese Verbraucher abgeschaltet waren bzw kein Kurzschluss vorliegt.
Ein automatisches Wiedereinschalten kann 6 x erfolgen bei eingeschalteter Kl. 15.
Diese Sperre wird aufgehoben durch Ausschalten der Kl. 15.

Um die Ausloeseschwelle beim gleichzeitigen Einschalten mehrerer Verbraucher nicht zu erreichen, koennen bei der FH-Steuerung gleichzeitig nur 2 gleichzeitig angesteuert werden. Werden mehrere Tasten gleichzeitig betaetigt, so werden nur die zwei ersten Befehle ausgefuehrt.
Sollte bereits bei 2 eingeschalteten FH die Ueberlastgrenze ueberschritten werden, so wird ein FH abgeschaltet. Dabei haben die FH vorne Vorrang.

in brief: 6 times overload for
-wenn laenger als 60 Sekunden ein Strom von ueber 36A oder
wenn laenger als 0.3 Sekunden ein Strom zwischen 36 und 60A oder (Ueberlastung)
-wenn laenger als 0.1 Sekunden ein Strom groesser als 60A fliesst (Kurzschluss)

and the GM switches that function completely off and switches it on when ignition has been switched off once for 60 seconds. Terminal 15.

So you might have somehow too much load there sometimes.
See under 10 ZKE

ZKE

ZKE
that is the complete ZKE = central chassis electronics technical training manual.


TSH = door lock Heating—-Tuerschlossheizung
ZV central locking system - Zentralverriegeling
ZS = Central locking system inhibit device
FH= electric window
SHD = sliding/ lifting roof (from ETK)—-Schiebe-Hubdach

[Ken35i]

Thanks Shogun, all but the front-passengers door are closed and locked. I cannot open them and they must be double locked also.

I'll try these simpler fixes first then, if they don't work, I'll have to pick the drivers door apart from the outside, through the window, which won't be fun.

Thanks again :-)

[shogun]

read this thread from the E32 forum, E32 and E34 have the same GM, maybe you might be able to
Disable Power Locks (and Deadlocks)

in the second post I have a link to show wjat do to on the electronic side and which wires etc, should be similar to the E34
Disable Power Locks (and Deadlocks)

[Ken35i]

Hey again all,

It's been a long time, I know. But things get in the way.
I've finally fixed the problem!
Initially the doors were stuck locked and closed which means I couldn't get into the door. As stated in my first post; I couldn't unlock the door via the boot/trunk. But one day it did! Thankfully.
So I left my doors unlocked for a number of weeks until parts arrived and the time to do it.

I went for the micro-switches in the drivers side door (pictured). These 3 switches make the car: locked, unlocked or double locked. They are pressed by the cam lobes on the lock barrel, for those who don't know.
Well, one of the switches (the "lock" switch) wasn't clicking like the others and figured that it must be stuck "ON" hence why couldn't unlock the doors and my windows would whined up when I turned the car off. A test with the multimeter on the 4 pins on the plugs also indicated that this switch was not switching.
So replacing this switch block solved the problem.
Part number: 61311390886

[shogun]

Many thanks, Ken, for informing us the way you solved the problem. That will help others in the future.

[genphreak]

Sweet! I've had them out before but never pulled the Micro switch and taken a close look. Clearly they are easily replaced if you have a problem with one... Ken, as Shogun said- thanks for sharing!