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

Power, Grounds, and DLC


Object Number: 675607  Size: FS
Master Electrical Component List
OnStar Description and Operation
Inputs and Outputs
Batt 3
DLC
G203, Page 2 of 2
Figure 2:

Inputs and Outputs


Object Number: 675609  Size: FS
Master Electrical Component List
OnStar Description and Operation
Vehicle Communications Unit ( VCU)
Power, Grounds, and DLC
G402, Page 1 of 2
G402, Page 1 of 2
Cellular Communication Schematic Icons
Cellular Communication Schematic Icons
Cellular Communication Schematic Icons
Figure 3:

Vehicle Communications Unit ( VCU)


Object Number: 675614  Size: FS
Master Electrical Component List
OnStar Description and Operation
Inputs and Outputs