Jeep 2014 Grand Cherokee Owner's Manual page 228

226 UNDERSTANDING THE FEATURES OF YOUR VEHICLE
If an object is detected in the left and/or right rear region, the
display will show a single arc in the left and/or right rear
region and the system will produce a tone. As the vehicle
moves closer to the object, the display will show the single
arc moving closer to the vehicle and the tone will change
from a single 1/2 second tone to slow, to fast, to continuous.
Slow Tone
Single 1/2 Second Tone