GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2003 🢒 Montana Ext. 🢒 Body and Accessories 🢒 Cellular Communication 🢒 OnStar Schematics
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)
Key Cylinder Switches
G200, Page 1 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