Have Mercedes Questions? Ask a Mechanic for Answers ASAP
It almost always is a faulty front passenger door control module. The door control module is actually the seat switch on the door. It controls all of the functions of the door except the locks. I suggest replacing the door control module with a used one on ebay. To replace it is very simple, just use a plastic wedge or flat blade screw driver to pop off the wood trim strip above the door handle. Then you can loosen the 5 or 6 T-20 torx screws behind the trim. Pop off the inner cover of the inside door handle/release lever and loosen the last remaining screw. Now the whole door control module/seat switch assembly can be replaced. You shouldn't need to program it to get it working again. Let me know if you have any more questions before you decide to rate me, thanks!