Circuit/System Description
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 LF door handle antenna is located in the left front door handle assembly and is used as a short range low frequency (LF) transmitter. As a vehicle with locked doors is approached with a key fob and the exterior door handle is activated, the keyless entry antenna transmitter broadcasts a challenge to the key fob in an approximately 1 meter range. If the response from the key fob via radio frequency (RF) is valid, the locked door will be passively unlocked/unlatched and allow the door to be opened.