I"m wondering if there is not a physical wiring issue with the common CAN BUS. That would explain why NO module respondes.
I think UrbanE's advice is sound.

There is one guy with a DRBIII emulator in the Dallas area, he lives near Fort Worth - his name escapes me now, he's the guy who set my cooling fan speed.
I"ll message Char in Fort Worth for his name and see if I can contact him on Facebook.