Dodge 2009 Nitro - Manual (Page 144)

The warning display contains two sets of yellow and red
LEDs, one set to warn of obstacles behind the left rear of
the vehicle and the other set to warn of obstacles behind
the right rear of the vehicle. The driver can view the LEDs
either through the rear view mirror or by looking at the
display above the rear window.
When the ignition is turned to the ON position, and the
system is enabled, the warning display will turn on all of
its LEDs for approximately one second. Then, the system
dimly illuminates the two inner most LEDs when it is
detecting no obstacles.
The Rear Park Assist System is active when the ignition is
in the ON position, and the system is enabled, and the
driver shifts the transmission into the REVERSE position,
and the vehicle speed is less than 11 mph (18 km/h). The
following chart shows the warning display operation
when the system is detecting an obstacle:
142 UNDERSTANDING THE FEATURES OF YOUR VEHICLE