Jeep Grand Cherokee Owner's Manual page 234

232 UNDERSTANDING THE FEATURES OF YOUR VEHICLE
When displayed, static grid lines will illustrate the width
of the vehicle while a dashed center-line will indicate the
center of the vehicle to assist with aligning to a hitch/
receiver. The static grid lines will show separate zones
Red
Yellow
Green
Zone
that will help indicate the distance to the rear of the
vehicle. The following table shows the approximate
distances for each zone:
Distance to the rear of the vehicle
0 - 1 ft (0 - 30 cm)
1 ft - 3 ft (30 cm - 1 m)
3 ft or greater (1 m or greater)