K61 Sunroof Control Module: Programming and Setup: Notes
WARNING: This page is about a different car, the 2020 Buick Regal TourX, 2020 Buick Regal, 2019 Buick Regal TourX, and 2019 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.
When replacing the sunroof motor/control module, the sunroof motor/actuator initialization/teach procedure must be followed.