Console Passive Antenna
WARNING: This page is about a different car, the 2010 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.
The console passive antenna is used to transmit low frequency communications to the keyless entry transmitters to determine if there are any transmitters inside the vehicle compartment.
The keyless entry console passive antenna is located under the trim below the cup holder. The antenna is controlled by the RCDLR. When the vehicle's start/stop button is pressed or when the doors are closed, this antenna sends out a low frequency challenge to the keyless entry transmitter, which begins the passive communications.