I must apologize, I have scanned through all the service manual information and cannot find exactly what drives the speedometer, or the cruise control.
I can find all the wheel speed sensors, but they all seem to feed just the ABS module.
Also, the automatic transmission has 2 speed sensors in it, but they just seem to feed the TCM.
I guess it is entirely possible that either or both of these put messages on the CAN bus that the PTCM reads to determine the current vehicle speed, and thus control the speedo and cruise, but I can't find anywhere that it is stated.
Bottom line : I ain't got a clue.
( In my business, this issue would need to be escalated to level 2 or level 3 people for an answer, but unfortunately we have NO L2/L3 people, unless someone wants to chime in )