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

Power, Ground, DLC, OnStar GPS and Cellular Antennas


Object Number: 794961  Size: FS
Master Electrical Component List
OnStar Description and Operation
Keypad Microphone Signals
Fuse Block Rear - T SIG/HAZ, STOP LP, AUDIO and CD Fuses
Fuse Block Rear - T SIG/HAZ, STOP LP, AUDIO and CD Fuses
Serial Data Class 2
G305, G310, G404, and G303
G401 - 2 of 2
Figure 2:

Keypad Microphone Signals


Object Number: 794966  Size: FS
Master Electrical Component List
OnStar Description and Operation
Power, Ground, DLC, OnStar GPS and Cellular Antennas
G402
G402
Cellular Communication Schematic Icons
Cellular Communication Schematic Icons
Cellular Communication Schematic Icons