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

DLC Power Ground and Low Speed GMLAN


Object Number: 1794663  Size: FS
Master Electrical Component List
Data Link Communications Description and Operation
Control Module References
High Speed Serial Data
Rear Fuse Block B+
PRK LAMP, DRL Relays, IP HARN MDL, LT PRK LAMP, RT PRK LAMP, DRL Fuses
PRK LAMP, DRL Relays, IP HARN MDL, LT PRK LAMP, RT PRK LAMP, DRL Fuses
G300
Data Communication Schematic Icons
G300
Figure 2:

DLC High Speed Serial Data


Object Number: 1794672  Size: FS
Master Electrical Component List
Data Link Communications Description and Operation
Control Module References
Serial Data Wake Up
Power, Ground, and Low Speed GMLAN
Data Communication Schematic Icons
Figure 3:

DLC Serial Data Wake Up


Object Number: 1794676  Size: FS
Master Electrical Component List
Data Link Communications Description and Operation
Control Module References
High Speed Serial Data
IGN SWTCH, STR/WHL/ILLUM Fuses