Jeep Grand Cherokee SRT8 2012 Owner's Manual page 233

UNDERSTANDING THE FEATURES OF YOUR VEHICLE 231
The system will indicate a detected obstacle by showing
three solid arcs and will produce a one-half second tone.
As the vehicle moves closer to the object the EVIC
display will show fewer arcs and the sound tone will
change from slow, to fast, to continuous.
3
Park Assist System OFF
Slow Tone