Circuit/System Description
WARNING: This page is about a different car, the 2009 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.
The LF door handle antenna is located in the left front door handle assembly and is used to establish low frequency (LF) communications with the keyless entry transmitter. As a vehicle with locked doors is approached with a keyless entry transmitter, known as an electronic key, and the exterior door handle is activated, the keyless entry antenna broadcasts a challenge to the transmitter in an approximately 1 meter range. If the response from the transmitter via radio frequency (RF) is valid, the locked door will be passively unlocked/unlatched and allow the door to be opened.