Keyless Entry Transmitters
WARNING: This page is about a different car, the 2007 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.
The keyless entry transmitter are used to passively or actively lock and unlock the vehicle.
When any one of the 4 allowable programmed transmitters are challenged by a keyless entry antenna by operating either of the front exterior door handles, they will passively send a radio frequency (RF) signal to the remote control door lock receiver (RCDLR) via the door antennas; the RCDLR will then interpret this communication and either allow entry into the vehicle or deny it.