Circuit/System Description
WARNING: This page is about a different car, the 2021 Buick Enclave. However, it is still accessible from the selected car via links, so may be relevant.
The AM/FM antenna is integrated into the rear spoiler. The radio receives both AM and FM signals from the rear spoiler antenna. The antenna is enabled when the radio is turned on. The radio provides battery voltage to the antenna using the center conductor of the antenna coaxial cable.