89 Eldorado Door problems
 

I have an 89 eldorado 2D. My passenger door ajar message keeps coming on. I looked around the door framing and door edges, nothing seemed to be stuck or blocking the door from losing. I tried slaming it, and that didnt work. I held the button to the senser down and it still says door ajar. I didnt know if there was another button or not. the door isn't jamming. what could be the problem