Has anyone had any luck with sending custom messages to the NAV in the DIC? I don't use the Nav anymore since it is old and now the telematics unit is dead, so I want to repurpose that section of the DIC and put some custom information from the car's performance. Due to the forum's excellent work I have all the PID's I need for the performance I want to measure but there isn't much documentation on the actual frames to send on the GMLAN. I sniffed the high and low speed. It looks like most of the DIC updates happen through the low speed side. I can see where the street is getting set:
Does anyone have any notes or done this before? It is very slow going picking through the frame by frame. Thank you!