Circuit/System Description
WARNING: This page is about a different car, the 2018 Cadillac XT5. However, it is still accessible from the selected car via links, so may be relevant.
The active antenna system uses an antenna integrated into the rear spoiler. The antenna amplifier receives both AM and FM signals from the rear spoiler antenna. The radio antenna amplifier is enabled when the radio is turned on. The radio provides battery voltage to the antenna amplifier using the center conductor of the antenna coaxial cable. When a 12 V signal is seen by the amplifier on the center conductor of the antenna coax, both AM and FM signals are amplified.