Visual/Physical Inspection

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.

Inspect for aftermarket devices which could affect the operation of the automatic transmission shift lock control.
Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.