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

Vehicle Theft Deterrent (VTD) System
Object Number: 2062774 Size: FS
Figure 2:

Door Modules and Horn
Object Number: 2062779 Size: FS