Possessed car UNLOCKS ITSELF WHILE DRIVING (210 '97 )
 

Last week the car started doing something very unnerving. While I was driving the car would UNLOCK ALL THE DOORS and turn on the dome light as if a door were open! I mean the locks would actually raise themselves up into the unlocked position and "click" menacingly as if the doors were about to open. The only way to make the dome light go off was to open and then close the driver's side door. Simply pushing the door lock button had no effect.

Now the problem has gotten worse. Opening and closing the drivers door no longer fixes the problem. Nothing I do will cause the doors to stay locked or the dome light to go off (except switching it to the "always off" position.) Also the floor lights stay on all the time as well -- even when the car is turned off, the key removed, the dome light switch set to always off and the car locked with the remote.

I am afraid that my battery will be run down by the floor lights always being on. More importantly, what could this problem be? A fuse? Help!

It seems obvious to me that your door switch is faulty. There should be a little black thing coming out from the B pillar when your door is open. It must be faulty...
Sorry, but I don't know the repair on this one? I assume you must remove the interior trim on that pillar (which is much easier than it looks) to inspect it even further. Replacement should be relatively easy?

Again, good luck!

could be....?
 

David, thank you so much for your reply. I am a relative newcomer to this board and I am overwhelmed at the level of support that people have been giving me!

One of the first things I tried when the problem first happened was to look at the door latch on the B pillar. It is indeed a little black latch but I could not see anything unusual about it. The door (appears as though it) closes normally and the drivers latch seems to behave just like the passenger side. (sigh) I guess I am forced to consult my extorter -- I mean dealer. :-)

Time to call a holy man and banish the demons!!!:eek:

There should be a black round rod (door switch) about 1/8"diameter located just below the door latch. If you press in the door switch with your finger the light should go off at about 3/4" of travel.

on the right track...
 

Yep that is the problem; the black backing plate that keeps the button in place is cracked. So, what happens is that that when I close the door, the door pushes the entire button assembly into the frame instead of only pushing the button in. As a consequence the button never gets fully depressed.

I "fixed" it by wedging a piece of folded up paper towel through the crack into the space behind the button assembly (thus acting as a backstop to keep the assembly in place and allowing the button to be depressed).

Thanks to all! All I can say is I LOVE THIS FORUM

Thanks !!!
 

Hey guys !

You rock ! :D

I had the exact same problem for about three weeks! Dome lights were switched on and doors were unlocking even when I was pressing the brake pedal (deceleration I guess was causing the switch to move slightly...)

I brought the car last week to a Mercedes dealer and they could'nt identified the problem!!! Now guess what, I'm gonna go there, buy a switch, replace it myself!

A little McGuiver in all of us
 

May not be an "Official" repair, but it works...Cool...

An old military axiom: "If its stupid and it works, then its not stupid." :D