figured it out
So, I ended up tearing apart the door. I only managed to break one of the plastic clip fasteners on the inside panel. (No applause, please...) I nearly forgot to take out the plastic screw in the part of the panel that faces out the back window... Anyway, it all came off without too much trouble, then I was able to peel a small portion of the rain shield off and get to the opener/hook mechanism. I found that the tiny little servo/motor that disengages the lock was made out of black plastic and was broken. It attaches to the side of the lock mechanism and had cracked where it attaches, so the little plastic gear was not meshing with the gears on the lock, so the sound I was hearing was the little gears making a small grinding noise when the lock was engaged or disengaged. It was easy to see the cable mechanism which unlocks and disengages it, and the door opened easily when I pushed it. The lock mechanism, which is part servo/motor and part black plastic and part hardened steel is attached to the door with three torx screws and is easily removed. It costs around $120 and is on order. For the time being my door does not open on command. By the way, this all started when the door shut on a belt from a travel bag. The Ford place tells me the mechanism has been upgraded from the original part two times, so hopefully this will not occur again...