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

Onstar Power and Grounds


Object Number: 857920  Size: FS
Master Electrical Component List
OnStar Description and Operation
Onstar Inputs and Outputs
BATT Main 1 and Fuse Block - I/P Fuses
Data Link Connector (DLC) Schematics
Key Cylinder Switches
G200, Page 3 of 3
Figure 2:

Onstar Inputs and Outputs


Object Number: 857927  Size: FS
Master Electrical Component List
OnStar Description and Operation
Onstar Power and Ground