Yep - if you notice the speed interface unit has 2 outputs, 1 goes to the speedo and CC and the other to the Trip computer. These have different pulse output per mile.

You mentioned the TC works, if this is correct then the speed sensor is working.

 

It's just a few wires... I may just go ahead and rewire the while darn thing (speedo wiring) from front to back... Everything is wide open and it's not that much wiring... Still, wiring makes me skerd, lol...