Urgent help - replacing central locking actuator

[Paul_540i]

My drivers central lock actuator is shot, meaning i have to lock/unlock with the key. I have the later type locks that do not require synchronising (nor is it possible to do so).

I have already removed the door card.

How do you get the locking actuator out of the car? I have the later type actuator, small black box which is attached to the lock mechanism itself. I remove the electrical connector and it's getting voltage pulses when operating the central locking, so safe to say the actuator is shot.

I removed the three torx screws holding the lock mechanism in place, and it can be moved around but I can't get it out of the car becuase of the window runner. What is the technique for doing this? I've heard failed actuators are very common so there must be a known method.

Cheers.
Paul.

[GaryE]

I've recently removed mine on a 520, don't know if it will be the same - but after removing the 3 screws move the lock and actuator down, and remove by turning the whole block to the right (whilst attmepting to get the device out of the car), I did this by getting the connector/actuator out first and then the lock body just followed on.

I had same problem removing mine - I think it looks trickier than it actually is, keep trying buddy...

[Javier]

window up, its one screw in the rail, behind the guide, pull down when screw is out.

To replace, stick it up to the panel hole, attention to the hook.

All messing behind door panels require unplugging window motor for safety reasons.

Think I remember you can pull out the actuator without removing the lock mechanism.

Javier

[Paul_540i]

Can't see any way to remove the actuator. I was trying to twist it out as suggested, then noticed the outer handle rod is still connected, aaargh! If BMW insist on fitting such crap quality lock components, they could at least make it easy to replace. I've never had any central locking component fail on any of my other cars, and that includes a vacuum pump Audi system.

I've given up for tonight as it's now dark here. Any ideas on removing this actuator without removing the lock, or if I need to remove the lock how do I disconnect the outer handle rod?

Cheers
Paul.

[Javier]

and has no tie rods nor connections other than the electrical plug. There aren't screws or latches. Just pull the plastic black box apart from the lock hardware.

Gary can confirm, as he recently worked with one of them.

Javier

[GaryE]

Yes the actuator (black box) does snap on, only a indent type catch on one side, I used a flat head screw driver to gently pry this up and the actuator slips off. Its only a plastic surround.

Good luck.

Gary

[Paul_540i]

OK thanks for that. It did look like it was separating from the lock mechanism but I didn't want to force it. Will try and get the actuator out without having to remove everything.

Cheers
Paul.

[Paul_540i]

Nice one... I now have the actuator in my hand, removed without having to get the lock mech out.

Originally, the mechanism wasn't moving at all. Moving the slider by hand would lock or unlock the rest of the car, so it was sending out signals correctly. I tried moving the gear motors around a little, plugged it back in and the actuator sprung to life! However the problem now is that if I lock with the remote, the actuator will now operate in the lock direction, but immediately it will unlock again and cause all the other locks to unlock. It will then lock again, and the cycle repeats until I disconnect the actuator.

So basically with it connected as soon as I lock with the remote, all the doors lock and unlock repeatedly. I guess there's some kind of configuration the actuator needs to be in before I connect it? Or am I doing something stupid and it will work if I actually push it back onto the lock mechanism rather than just watching it while dangling from its electrical connector?

I'm baffled, but feel like I'm getting there! I get the impression this actuator is fixable, which is good as I don't have a replacement at the moment.

Cheers
Paul.

[Javier]

If not, just insert your thumbs, one side each, between the black plastic cover and the clear plastic base, with the electric plug socket facing forward, then use your index fingers to pull up apart the plug socket form the plastic cover.

This will give you access to the inner part without much disassembling. If you want to further disassemble, take good care on observing the relative position of the sliders inside the clear plastic cover. There is a slider attached to the cover (the one that actuates on the lock) and there is another slider in a motorized screw like axis, inside the body. Look trough the plastic cover, against a light source to note their location.

Check carefully the white plastic gear, if there are missing tooth or tooth damage, the actuator may fail under mechanical load (sorry to have shadowed your happiness).

Take the opportunity to check proper operation of both micro switches. They are single pole double trough, so continuity should be from the stand-alone pin (common) to one of the paired pins, depending on pressing the switch button. If you do not want to disassemble, just test the switches operating manually the slider (for the longer pins switch) or operating the white plastic gear with your fingers for the short pins switch.

Also take the opportunity to clean the motor contacts. There are two metal pin contacts in the black plastic motor receptacle; they plug in the motor white plastic cap. This will require further disassembly. If you do not dare, just exercise the contact by pulling the motor from the receptacle (a very little bit) at the end with the white plastic cap, and push it back, repeat a couple times.

Yes you need to coordinate the position of the actuator and the system. Just plug it wile the actuator is in the unlocked position, and all the rest of the locks are also unlocked.

Let us know your findings.

Javier

[Paul_540i]

Aaaargh! This car is driving me insane. Checked the microswitches with a meter, all working perfectly. No broken teeth on the gears, indeed no sign of any damage. Motor was working fine when I plugged the actuator back in and tested with the remote, although I had to stop the slider from bouncing at the end of its stroke or else it would continually lock/unlock. I expect this happens because there's nothing connected to the actuator to damp it - the door mechanism would usually do this.

So everything looks fine, I got it back into the car (after about an hour!) and..... exactly as before! Lock or unlock the door with the key or button, and it locks or unlocks all the doors. But try from the remote, and the drivers door does nothing, not even a whimper from the motor.

I'm totally baffled by this, my only guess is that there's some wear in the actuator meaning it only works on a very fine tolerance and when connected to the door it's outside that tolerence. Suppose I should just buy a new one, although I'll be very frustrated if I install the new one and it doesn't work.

I also noticed that the build date on the part is 1997. Since mine is a 1995 car, it's already been replaced. I see reliability of these parts is high :rolleyes: this is only one door so I wonder how many have been replaced in all the doors.

Cheers
Paui.

[Javier]

at passengers door, should be the same result as with remote. The driver's lock actuator motor is not working; actually, you shouldn't be getting double lock (arrest) at the driver's door.

I would operate the actuator in my hand, imposing some mechanical load in the slider, so to force high motor currents to emulate normal working conditions. Your problem is the motor not working, so you should focus on the short leads micro-switch. If it reaches a position in which both paths are opened, the motor will not work any longer, until you manually move the motor slider and force a contact closure.

Guess you have a problem in the power circuit feeding the motor. The motor selector micro-switch (short leads) is suffering the more severe duty in the circuit, as it turn off the motor when reaches the travel end, note there is a parallel capacitor at the motor to easy this duty. I would try switching both micro-switches, as the other one only generate position signals to the central module, and contacts should be in very good shape. When soldering this motor micro-switch, be sure to reach the proper position, so the motor slider operates it. Micro switches are tight closed, so would be almost impossible to spray some contact cleaner, or perform any maintenance operation.

Switching the micro switch you are risking to have pop up operations when locking the doors, I feel that it is a very low risk as once it is operated a couple times with almost no current, it will get cleaned and will stay for long.

I wouldn't dream to find the micro switch in my country, may be you are more fortunate.

Javier