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

Low Speed LAN


Object Number: 1856145  Size: FS
Master Electrical Component List
Data Link Communications Description and Operation
Control Module References
High Speed LAN
B+ Bus Bar - 2 of 2
SIR Schematic Icons
G300 - 2 of 2
Figure 2:

High Speed LAN


Object Number: 1856159  Size: FS
Master Electrical Component List
Data Link Communications Description and Operation
Control Module References
Low Speed LAN