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

Power, Ground, and DLC


Object Number: 1473365  Size: FS
Master Electrical Component List
Radio/Audio System Description and Operation
Body Control Module (BCM) Programming/RPO Configuration
Speakers
B+ Bus - Underhood Fuse Block
Digital Radio
Data Link Connector (DLC) Schematics
OnStar Schematics
G300, G301, G302, and G303
Figure 2:

Speakers


Object Number: 1473366  Size: FS
Master Electrical Component List
Radio/Audio System Description and Operation
Body Control Module (BCM) Programming/RPO Configuration
Digital Radio
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: 1473384  Size: FS
Master Electrical Component List
Radio/Audio System Description and Operation
Body Control Module (BCM) Programming/RPO Configuration
Speakers
Power, Ground, and DLC
Data Link Connector (DLC) Schematics
Entertainment Schematic Icons
G300, G301, G302, and G303