Yes, my VSS wires go to the PCM. Without it, the PCM doesn't have any referencing speed signal coming from the vehicle. I also have the DRAC box behind the glove box and ended up jumping the wire from the Cruise control right to the speedometer wire, thus bypassing the DRAC box. I was having Cruise control issues and it ended up being the '99 cruise control box that I got from the Silverado 6.0 donor vehicle was junk. I just ended up using my '93 cruise control box and switched out the cable from the '99 box so it would reach the throttle/air valve at the front of the engine.