unlock,locks again immediately

[Paul in NZ]

not everytime but now and then,is this related to the boot hinge wiring or is always related to a door lock actuator or microswitch.How can you track down which actuator or switch it is?

[Javier]

For lock - unlock, in 1989 models, the only monitored locks are Driver's door and Trunk lid. You can verify it trying to lock all the doors with the passenger's door knob (it is not supposed to work).

If the problem does not show when you operate the trunk lock with the key (to the horizontal position, counter clock wise I think), or the lock does not work, it should be the trunk lock, and then probably the hinge harness (Remember Doogie's issue?).

If the problem does not show when you operate (lock) the driver's lock with the knob, or the lock does not work, it should be the driver's door lock, probably the micro switch inside the actuator.

For unlock - lock, I don't know, my car also has a estrange behavior in which some times when I stop to let a passenger out, and I unlock the doors pulling the knob or the handle, It locks again. Have not debug, nor study this as don't bother me enough!

Javier

[Kalevera]

Hey guys. My DS does the exact same thing (unlock and then quickly locks itself again, usually when I return the key to center position) occasionally, ONLY when it's cold, and when it has recently rained. This is accompanied with the DS staying locked (all other doors unlock), and it ONLY happens from the DS cylinder (all others will open it at all times). The lock actuator was replaced recently, and I think the microswitch might be the problem. But, like Javier said -- haven't found it annoying enough to troubleshoot ;)

best, whit

[genphreak]

Gee we all have the same problem, and the same response... (I can't be bothered quite yet...) :D Hahahhaaha... can't wait till one of finds out, it is what this community is all about! I'll be looking into it (with any luck) at some point... I wonder whereabouts on the boot harness the problem lies... at a movement point perhaps.... ;) GP

[Kalevera]

yeah, I pulled the cover off of the wire wrap there a while back; mine looked fine. I think it has to do with the microswitch on the ds lock cylinder in my car -- that's the only way to explain why it happens after it's rained & it's cold (ice/water freezing something up in there).

[Paul in NZ]

yes javier it is only the unlock/lock at this time with the key I can only say it happens from the drivers door (with the key). The passengers knob doesnt operate the other doors but i can lock or unlock the car from the passengers door with the key,and last time i tried the lock and unlock worked from the boot......

[Dan in NZ]

I had that problem when I first got my car. Replaced the central locking fuses under the back seat, and it hasn't happened since (2 years).

[genphreak]

I had that problem when I first got my car. Replaced the central locking fuses under the back seat, and it hasn't happened since (2 years). I'll give this a shot. Thanks, ANZAC brother!

[Nick.Hay]

My '90 535i has the lock/unlock issue. I've noticed that my hinge harness is a little shabby, and if I lock the boot (lock in horizontal position), then the central locking behaves itself, and works as normal. :)


Hmmm.... Maybe I should get that loom fixed!!

[Javier]

Javier

[Paul in NZ]

You can verify it trying to lock all the doors with the passenger's door knob (it is not supposed to work).


Passenger's door knob should open all the doors.

huh??

[Javier]

to unlock the system, but not to lock it. The micro switch is there but not connected to the GM (not used). This is what I call non monitored lock, as not having this contact wired will prevent GM to know if Passenger's door did lock or not.

In later models (from 1992), it is wired to the GM and the knob will unlock/lock the system, and be a possible cause for the immediate unlock after lock behavior.

See pictures comparing both systems.

Javier

[Paul in NZ]

uh huh i should learn how to read!!,i am going to try dans fuse idea but i suspect its the microswitch on the drivers door.....

[Javier]

are F30 and F31, but doubt they are gone unless other symptoms (non working knobs, or the lock-unlock reply syndrome. No losses checking them though.

Try to record any other weird things wile the problem shows, or even making an exhaustive audit of the Central Locking system operation. Operate in every possible way under any possible status, record evry thing. Any miss behaving can put some light to the problem.

I only have seen this unlock-lock reply issue with the engine running, not sure if even in drive position in transmission. As I told you, only when making a brief stop to let somebody in, or out. I will put extra care from now on in order to learn a bit of this problem.

Javier

[Dan in NZ]

I guess I was just lucky it was only the fuse!

[Paul in NZ]

where are 30 and 31 on a dec 1989 manf euro 535i,#bf01045

[Dan in NZ]

Mine were under the back seat. The ones under there don't tell you what they do, but I think the central locking ones are the fuses that you don't have to remove the black cover for. It's been a while...

[Javier]

under LH side rear seat, for 1989.

Javier

[Paul in NZ]

ok i have been observing this,the passengers lock knob poerates a s you say javier,everything seems ok at the boot.The other day i t took three attempts to get in,and all knobs were up except drivers door ,relock unlock and all knobs came up..i have a suspicion its the drivers actuator.......is there a procedure on e34 .net.....what does the microswitch do,tell the gm weter the dooris locked or unlocked cos it could be that to right??

[genphreak]

I'll give this a shot. Thanks, ANZAC brother!

I'll be back w more... :) GP

[genphreak]

exactly the same poop for me. when it's cold or when it has rained but, mostly when it's cold. it hasn't bothered me enough yet either except for this one time ... it was about minus 30 degrees C, i started her up, got out to scrape the frickin ice of the windows, closed the door and ..... click .... she locked me out :( bummer ....my spare key was at home about 15 miles away ....at least the car was nice and warm inside when i finally got it unlocked :D
Good point RJ, thanks.

OK everyone, I've noticed the following affects my the level of 'operational recalcitrance' my car's locks exhibit;

Swapping th fuse has not fixed it (perhaps a little not sure yet due to the intermittency of the problem)

Happens for me more if it is a cold, (but in Sydney, Oz) this means below 20 degrees centigrade not freezing.. no ice to deal with here :D

Happens more in the morning (perhaps as it is cold, perhaps because the car has been still for a while, battery voltage lower, etc)

Happens DEFINATELY if the car has not been driven for a few days, warm or cold.. probably voltage drop?

It may be co-incidental but whilst driving or alwyas when the engine is not running my indicators stop making the ticking sound (after their first flash). I think I have an earth loss somewhere, or my battery needs replacement. Goign to do some voltage monitoring. Has anyone had the problem, changed the battery nad then had ti go away? I am pretty sure my battery is good, a while ago I had ran out of fuel and it managed to turn the engine over for what seemed like 8 minutes straight..

I believe it is to do with voltage drop somehwere in the lock control.

This might explain why changing a fuse might help, temporarily perhaps (any comments Paul?), as old fuses can cause a small drop can they not?

[Paul in NZ]

mine seems more likely to do it in the mornings,or after a full day at work.....hmmmm and it seems worse still say on a onday after perhaps not driving at all during the weekend...my battery is fairly new,it has just started doing this...to rieterate i unlock the car and it relocks itself.....

[Javier]

inside the actuator is the actuator micro-switch (only one in your 1989 car). The micro-switch reports to the GM the status of the lock (= knob position). It is useful for two things.

First, to know the response to the lock command (only in driver's door and trunk for 1989). I'm almost sure the intention was to monitor the trunk lock, as contrary to door locks, cannot be monitored visually trough the knob position.

Second, to receive operation commands from the knobs and the trunk lock (driver's door knob can not command a lock, only unlock, this was fixed from 1992 on).

In my car GM, and would bet yours too, the reply command is only issued after a failed lock attempt (By reply command I mean an unlock command following a faulty lock command. Faulty because driver's door or trunk did not lock, also passenger's door from 1992).

The reply command is not issued after a faulty UNLOCK command, but yes, I have experienced something similar. Today I have been fooling with my Central lock system, and was able to reproduce the situation simulating both doors unlock failure, but notice an important fact.

Wile the GM reply command to faulty lock attempts will work no mater what happened to the lock, as long as it ended unlocked after a lock attempt, the reply command to a faulty unlock only operates when the faulty lock actually got momentarily unlocked. So it is not a reply command, but only a lock request issued shortly after the unlock request.

This is easy to simulate, just jump into the car, keep your driver's door pulled up and ask somebody to lock the car with the key at the passenger's door. (Unfortunately, you can not simply push down passenger's knob with your other hand). You will get an unlock reply command.

Now push down driver's door knob to lock the system and pull up the knob keeping pushed down the passenger's door knob, no reply, try again pulling up passenger's knob keeping down driver's, also no reply, now, keep your hand over the knob, allowing it to move up a bit but keeping it to complete the movement so it will go back. Then you will have all the locks back locked.

Question is what can cause it naturally? Carefully observe the suspicious lock to detect a knob pull up attempt, this may confirm the momentarily rupture of the micro-switch contact, if so, I would try a good lube of the mechanical link and actuator itself. My guess is that the actuator fails to drive the knob the full travel, letting it back to lock position, issuing a lock order. It can only happen with driver's door (1989) or trunk if not in horizontal position. Rain and cold (freezing) may help making the linkage stiffer.

Let us all know your findings.

Javier

[Paul in NZ]

wow javier that is a perfect technical expanation of what I think is happening.I think that the actuator is at faut and was going to try to luble/clean/adjust things to see if i can fix this problem.Can the actuator from another door be swapped to the drivers door?

[Javier]

As passenger's door lock contact is not wired, exchanging may solve the locking issue, if the actuator is feeling tired (of course, some times, you may not succeed unlocking passenger's door, but will not get a lock command as a result).

Guess that cold weather, not necessarily freezing, may have to do with this issue, as old grease may get hard, imposing some extra load to the actuator. Also prolonged steady periods for the actuator may settle dusted grease, allow more corrosion in linkage joints, and in general make the mechanism harder to operate. It happens to all mechanism, if you let them a long time without operation, some extra breaking in effort will be required for the first attempt.

Javier

[Paul in NZ]

today after not driving the car all weekend it took threeor four attempts to unlock the drivers door,gummy door mech and or weak drivers actuator and or faulty switch.....its coming apart this coming weekend!

[Robin-535im]

I've heard that the trunk wiring can short out and cause this kind of problem. Look at the wiring loom that follows the trunk hinge and see if there are any shorts. You might search the archives too. It hasn't happened to me yet but IIRC, the trunk wiring's a big suspect.

HTH

Robin

[Javier]

Javier