This all started when I bought a slightly used 2004 C240 Wagon for my wife in a private-party sale. When I got it home I noticed the passenger window would not stay closed, if you used the "auto up" feature it would go all the way up and then back down a couple of inches like it was detecting an obstacle. I tried to resync the window using the method in the manual but it did not work and continued to back down when it hit the stop. The only way you could get it to stay all the way up was to hold your finger on the up button for a few seconds and then it would stay.
So when the car went in for its first service earlier this year I mentioned it to the service advisor. They kept the car overnight while they ordered a new regulator for it. When the tech opened the door panel he saw it had some broken glass from what I can only deduce was a break-in and he also noticed the window was not MB branded but regular Pilkington without the "star". The SA called me and stated that the problem with the window was not caused by the regulator but by the glass being "aftermarket" and the "wrong part" and said this is not a warranty repair but quoted $300 to make it right by replacing the window with a "star" part. I declined and decided to live with it.
Tonight I decided to try an experiment. I lowered that window and disconnected the negative battery cable. Then, after a minute or two I reconnected the cable and resync'd the window and - what do you know...it works perfectly now! All it needed was to have the stop point reset by wiping out the "memory" and then it could be set to the correct stop point by the resync method shown in the manual. Of course I had to resync the other three windows and reset the clock, but all in all a 5 minute job saved me $300.
Now I will ask you - do you think the dealership knew how to do this and just wanted to stick it to me or are they really such boobs that they didn't even know how their own window systems work???
Maybe both
To top it all off they still charged MBUSA to replace the regulator and 3.1 hours of labor under the warranty, even though this did not fix it!