GM Service Manual Online
For 1990-2009 cars only
Figure 1:

DLC Power, Ground, and Low Speed GMLAN


Object Number: 2085365  Size: FS
Master Electrical Component List
Data Link Communications Description and Operation
Control Module References
High Speed GMLAN
Figure 2:

High Speed GMLAN


Object Number: 2085367  Size: FS
Master Electrical Component List
Data Link Communications Description and Operation
Control Module References
DLC Power, Ground, and Low Speed GMLAN
DLC Power, Ground, and Low Speed GMLAN