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

OnStar
Object Number: 2080696 Size: FS
Figure 2:

Hands Free Phone Accommodation (WXS)
Object Number: 2081288 Size: FS