It's an hour's shop time to diagnose. Probably 100 bucks. I replaced my shift solenoid on advice from this board and it did not fix my shifting issues, but then that is on me because these folks can only offer advice based on what is posted on a problem.
Really though, even the dealer may not help. The experiences I've had with my local Lincoln dealer have been less than stellar. They can't find parts for the car and every time I go in they try and talk me into getting work done somewhere else. Worked too, next time I need anything including a new car I'll be going somewhere else even if I decide to buy another Lincoln (which isn't looking good as they only offer FWD and SUVs). So far as parts go, I've had better luck with the local Jag dealer getting parts, for the engine anyway.