Circuit/System Description
WARNING: This page is about a different car, the 2018 Buick Regal TourX and 2018 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.
The Steering Wheel Controls are divided into a right-hand set and left-hand set. The right-hand switch is connected to the IPC LIN serial data and provides input from the left-hand switches. The IPC identifies the switch selection and activates the feature.