03 Sun roof

I have a 2003 Impala with a sun roof. The roof use to, with one push of the button, open to vent position. I think with 2 pushes of the button it would slide aaaalll the way open. Now I have to keep tap tap tapping the button to get it to open all the way, Same to close the roof. Do you think it is the sunroof opening position switches, or the sunroof control module.... or what ?

Do I have to remove the whole headliner to remove the position switches ?