Remote Keyless Entry (RKE) Key Fob

The key fobs are used to begin the remote vehicle start request, then that begins the authentication request process by identifying the key transponder.

Courtesy of CHRYSLER GROUP, LLC

Transponder backup mode starting: 

There is a LF coil located in the KIN that can communicate with the key fobs transponder in close range if the fob battery is dead, and complete the authentication. In the event of a depleted key fob (1) battery, push the front edge of the key fob against the start button and hold it there for a few seconds to start the vehicle.