air bag question

[justinmoline]

Hello i have a 1994 buick regal grand sport about 140,000 miles 4 door 3.8. I was told that i needed a airbag discrimination sensor? What is this and where is it? what would make it go bad and is it something that could be done my self? Also how hard is it to change a window motot front passenger side? Thank to all!!!!