My central locking system works good but it will not lock the car from the driver door, either from inside or by using the key from the outside. To lock the car I have to push down the passenger side lock and then lock the driver door from the outside since you can't lock it when it is open. What part do I need to replace in the door that may be causing this issue? Locking the car on the passenger side works perfectly as it should.

 

Likely a vacuum connection (or vacuum operated switch) at the driver's door. I believe the main module is under the rear driver side seat. Check there for leaks.

 

Hmmmm !
If it's not a vacuum leak then I would suggest the actuator inside the drivers door ! Mind you the leak could be at the door not necessarily just at the vacuum pump ! Sounds like a door trim removal job maybe if leak check doesn;t reveal anything !

 

I've already removed the door panel once to replace the window regulator. Nothing too difficult. I think the issue is a component inside the door not under the backseat as the central locking system seems to function fine from the other door

 

If all the locks are going up and down, it's not a vacuum leak. From your post, it sounds like the problem is the inability to actuate the vacuum system from the driver's door. If that's the case, the failure is one of three places. The door actuator, the wiring in between it and the vacuum controller (under the back seat), or the controller itself.

The door actuator mechanism contains a switch that is connected by a clutch to the actual lock mechanism. When you operate the lock with the key the switch either connects the trigger wire to +12 or ground to lock/unlock the car. If that switch or the clutch is broken, this doesn't happen.

To test you will have to remove the door panel. Inside you will find the actuator which will be connected via a 3 conductor plug to the rest of the harness in the door. Unplug that connector and ground the blue wire on the harness side with a short piece of wire. If the vacuum pump operates, it's the switch/clutch in the actuator. I was have intermittent trouble with mine and it turned out to be a little corrosion in the mechanism - a few blasts of silicone spray and good as new.

If the pump doesn't run, it's either the controller itself or the wiring. You can do the same ground test on the blue wire right at the controller to rule out the wiring.

Good luck.

- FD

 

Thanks so much for the information. That will help me immensely because I am not totally familiar with the W124

 

Ahhh Flooby Dust You've taken the Words Right Out of My Mouth !
(hmmm maybe change your name to meatloaf) ! Hahahah

This might assist you also in your door woes !

80-900.pdf

 

I must say after owning it for a couple of months the W124 is superior in many ways to any BMW I've owned. Truly a brilliant and remarkable car. I've driven a 2011 C300 and the 300E, I think, drives way better and has more character. I'm 21 and some friends say my car is lame and 'grandpamobile' but they don't know what they're talking about and also have no taste!