Originally Posted by Chris_1

You might want to look at the rabs unit on the frame - pretty much in line with your door hinges. Not much ever really goes wrong with those, but it is 20 + years old. They originally came up with that system because the trucks had an issue with rear wheel hop under heavy braking at highway speeds. Other than that the system isn't really good for much (compared to modern ABS systems). A lot of guys will bypass it altogether.
But for tracking down an issue; the rabs module, rabs unit itself, the VSS, the trans speed sensor and the cruise control are all tied into the same circuit that feeds info to the odometer (PSOM) so it can feed info to the PCM so it can tell the tranny when to shift.
Those are the things that are in any way related.