Cd4e transmission

I have a 1998 Mercury Mystique with the 2.5l motor and 130000 miles on it. The tranny does not go into gear but I could shift it from park to 1st. When it is in neutral it acts like it is in park with or without the car running. And whatever gear it is in it makes a whinning noise from the tranny when I rev the engine. I also pulled a codes from the car and got a P1744. The trnny fluid was flushed last at 90000 miles and I just did a drain and refilled it today. I read up on the internet and know that these trannys have problems but I need to know were to start on finding the problem. I have automotive backround im just looking for a starting point. Any help would be great to get me started thanks.

Steve