GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2008 🢒 Lucerne 🢒 Power and Signal Distribution 🢒 Data Communications 🢒 OnStar Schematics
Figure 1:

UE1
Object Number: 1886692 Size: FS
Master Electrical Component List
OnStar Description and Operation
Control Module References
Figure 2:

Data Link Communication
Object Number: 1886700 Size: FS