GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2009 🢒 CTS 🢒 Diagnostic Navigation 🢒 Vehicle Diagnostic Information 🢒 Data Communication Schematics
Figure 1:

Low Speed GMLAN
Object Number: 2080710 Size: FS
Figure 2:

High Speed GMLAN
Object Number: 2080713 Size: FS
Figure 3:

Communications Enable
Object Number: 2080716 Size: FS