Spencer

Hi there all please go easy on me ... Right i have a 2002 grand voyager that has started to make a bit of a whinning noise. when you accelerate it revs high then jumps into gear and takes for ever to change up into next gear . i have the enginge magement light on and it is showing a p0700 code on the dash . now I've seen things on the internet about this code and some people say try changing the speed sensor ! could my problem be ths easy or is it something more drastic ? Any help would be appreciated .. Thanks Spence