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

Immobilizer
Object Number: 2180157 Size: FS
Figure 2:

Column Lock Key Receiver
Object Number: 2180158 Size: FS