Dodge Grand Caravan 2011 Owner's Manual page 185

UNDERSTANDING THE FEATURES OF YOUR VEHICLE 183
3
Park Assist OFF Slow Tone
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.