I have a 2001 S430 Mercedes. I have had problems with a locking sound coming from the back doors. This occurs about every 15 or 20 minutes while driving or even sitting at a light. I have had it to the dealer multiple times, but they say they cannot hear it so they can't fix it. (Of course they must be deaf). I now can recreate the sound by closing the door and letting the door automatically close the rest of the way. You can then hear the whining sound and the sound of the doors locking, then the trunk sounds like it latches. Can anyone help with this problem? I have posted this before under door locking but now I think it is the automatic door closure causing the problem. Anyone have a solution? The dealer has already replaced the PSE pump and motor located in the trunk.

 

Hi,
So whats the problem?
You have soft shut doors. This requires that the PSE pump runs to pull the door shut and once pulled in the latches have to fire to the second latched position.....as opposed to locked.
Although I don't have soft shut doors on my vehicle this appears to be exactly what is supposed to happen and I guess the dealer thinks so also.
Some feedback sound surely confirms that the doors have closed to the second latch position and are now safe rather than being on the first latched position which does not provide full secure latching.
Don't think you will achieve any change other than to your stress level.
Stuart.

 

The problem is, this sound occurs constantly while driving, not just once you close the door.