communication protocol ecm/tcm for 2007 trucks

[yevgenievich]

Very long and unlikely reach, but looking for detailed information on communication protocols used in the 2007-2009 gm trucks. Specifically protocols on ac and transfer case messages sent on a can bus.

 

[Poppy 87]

Pretty sure transfer case is high speed CAN and hvac is low speed CAN

 

[yevgenievich]

I found some info that manual shift transfer case actually tied direct to ecm. Would make it simpler. On AC side, trying to figure out actual string that would need to be sent on a can bus to enable ac