GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2007 🢒 Yukon Denali 🢒 Diagnostic Navigation 🢒 Vehicle Diagnostic Information 🢒 OnStar Schematics
Figure 1:

Module Power, Ground, and Serial Data
Object Number: 1704032 Size: FS
Master Electrical Component List
OnStar Description and Operation
Control Module References
Communication Signals and Control
B+ Bus - 1 of 3
AMP, ELEC RUN BOARD, ESC/ALC EXH, EXP/BRK MDL, INFO, and TREC Fuses
AMP, ELEC RUN BOARD, ESC/ALC EXH, EXP/BRK MDL, INFO, and TREC Fuses
G301
High Speed Bus - 1 of 2
High Speed Bus - 1 of 2
Low Speed Bus - SP200 - 1 of 3
Figure 2:

Communication Signals and Control
Object Number: 1789486 Size: FS
Master Electrical Component List
OnStar Description and Operation
Control Module References
Module Power, Ground, and Serial Data
G200 - 1 of 2