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

Power, Ground, Serial Data, and Digital Radio Receiver


Object Number: 2081519  Size: FS
Figure 2:

Base Radio - without Rear Seat Audio Controls


Object Number: 2081522  Size: FS
Figure 3:

Base Radio - with Rear Seat Audio Controls


Object Number: 2081524  Size: FS
Figure 4:

Audio Amplifier Power, Grounds, and Premium Radio Low Level Audi Outputs without Rear Seat Audio Controls


Object Number: 2081529  Size: FS
Figure 5:

Audio Amplifier Power, Grounds, and Premium Radio Low Level Audi Outputs with Rear Seat Audio Controls


Object Number: 2081529  Size: FS
Figure 6:

Premium Raio Amplifier Outputs


Object Number: 2081540  Size: FS
Figure 7:

Steering Wheel Controls - STW


Object Number: 2081546  Size: FS