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

Low Speed GMLAN


Object Number: 1764956  Size: FS
Master Electrical Component List
Data Link Communications Description and Operation
Control Module References
High Speed GMLAN
AMP, BCM, CHMSL/DM/LAMP, HVAC/RFA and RDO Fuse
AMP, BCM, CHMSL/DM/LAMP, HVAC/RFA and RDO Fuse
AMP, BCM, CHMSL/DM/LAMP, HVAC/RFA and RDO Fuse
G201
G203, G205, G207
Figure 2:

High Speed GMLAN


Object Number: 1764961  Size: FS
Master Electrical Component List
Data Link Communications Description and Operation
Control Module References
Communication Enable
Low Speed GMLAN
Figure 3:

Communication Enable


Object Number: 1844559  Size: FS
Master Electrical Component List
Data Link Communications Description and Operation
Control Module References
High Speed GMLAN