My sunroof doesn't stop at its closed position. If it is open, and i try to close it, pushing the button down, it continues its track until it rises its back side, like pushing the button upwards. How does it knows when to stop? Is there some mechanical or electrical instruction?
Thanks in advance.

Sorry guys.
I founded the answer in the
"Strange sunroof behavior in 560SEL" subject,
under the Harry Nashed's tip.
(Search before post...) I only will add that you have to turn the white adjustment wheel maybe 15 or 20 times to align the two holes. But it works. Thanks Harry