Thought I would share with you guys a little project I'm working on. Ive built the hardware and programmed the embedded software to output telematics information to the DIC/Cluster using the information from PID on the HSCAN bus. Can chime for upshift or if the Knock Retard is too high etc. The idea is to just plug the dongle into your OBDII port or hard wire it in if you want.
Effectively its a HS CAN / GMLAN Bridge with packet alteration and formatting
Vid should explain it all...
https://www.youtube.com/watch?v=kUIEAp0dkTA