Velcro

my cel was on so I pulle the codes(0104, and 0504) for the VSS and the a/t control unit. so I called my friendly nissan dealership, they said the speedometer it a computer itself and it tells the tranny when to shift, any of you know anything about this? It sounds about right but I wanna make sure before spending 350 bucks. they wanna do tests but I have no idea how much it'll cost, mines a 97 so warrantee is out of the question, unless I'm lucky enough to have it under some sort of recall.