on my 190E. The seat would not move back, and it was stuck at the very front, making entry and exit difficult and giving barely any leg room. I finally mustered the courage to take out the control switch module and opened it up. There is a very excellent write-up on doing this with pics. I forget who posted it, but he is to be commended. I'm glad it warned me about the ball bearings and that they could fly ecery where if opened too hastily. I was prepared, and opened the module with no grief. Anyhow, I cleaned the contacts with one of those tiny screwdrivers. I scraped the grime or black stuff off the circle contacts and cleaned the ball bearings and the module itself of dust. Then I reassembled, reconnect to door, and...seat still would not move back. I figured one or both of the copper contacts was not making contact with the circle metal piece. I repeated the process and this time I took out the two copper contacts for the back/front seat movement and bent them slightly a bit downward so that they would make a good solid contact. Voila, that did the trick.
It feels so goooood to have the seat move back!