I forgot about your internal version coding. The 2000 would need to be version coded too. The one I did my dvd install on was a 2000 as well. I also didn't know it was a 1998. One of the wires is a diagnostic wire, I believe it's yellow. This one joins up with another wire, I believe the diagnosis wire from the SRS. They share a common pin in the diagnostic plug. If these were joined together, i believe the tech could just go into the truck with SDS and the SDS would pick up on this info as though it were a 2000 or newer, at least for MCS. I'd try doing that, maybe that's why it's not working right.