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

Power, Ground, and DLC


Object Number: 1285565  Size: FS
Master Electrical Component List
Radio/Audio System Description and Operation
Speakers
B+ Bus - Underhood Fuse Block
Digital Radio (U2K)
Data Link Connector (DLC) Schematics
OnStar Schematics
G300, G301, and G302
Figure 2:

Speakers


Object Number: 1285574  Size: FS
Master Electrical Component List
Radio/Audio System Description and Operation
Digital Radio (U2K)
Power, Ground, and DLC
Entertainment Schematic Icons
Entertainment Schematic Icons
Entertainment Schematic Icons
Entertainment Schematic Icons
Entertainment Schematic Icons
Entertainment Schematic Icons
Entertainment Schematic Icons
Entertainment Schematic Icons
Figure 3:

Digital Radio - U2K


Object Number: 1285576  Size: FS
Master Electrical Component List
Radio/Audio System Description and Operation
Speakers
Power, Ground, and DLC
Data Link Connector (DLC) Schematics
Entertainment Schematic Icons
G300, G301, and G302