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.
When the radio is on, a discrete 12 V signal is supplied on the entertainment remote enable circuit to the Active Noise Cancellation Module / Audio Amplifier. This signal is used to control the power state of the component.