My 99 3.5L LHS will not shift. It seems to be in 2nd gear, will not shift. It makes no mechanical noises at all, will not respond when gear selector is in 3 or L. The speedometer works. My research has led me to believe it is the output sensor. Anyone know where it is located? Should I replace the input sensor too, being that they are only $17 each? How do I determine which sensor is input and output?
Thanks!

I fixed this same issue last year, but I assume you have fixed this by now?