wow, I really need help with this P0715er...

[strokin polo]

Ok, I am working on my 1999 Mercedes ML430 and am stuck between a rock and a hard place, so any help would be much appreciated! The wagon threw a P0715... which we all know to be the turbine speed sensor A circut right? Well I was advised that it could be the electronics in the trans so, I replaced the electric plate located behind the valve body with a brand new one from the dealer. While I was at it I threw a new filter in there as well, but thats neither here nor there at this point. To make a long story short, it is still throwing the code and will not let me out of limp mode...ie 2nd and reverse gears. I was told this also could be an input shaft speed sensor or an output shaft sensor...does anyone know if and where they are located?

Thanks for the help!

Charlie