Mercedes-Benz GLC : Vehicles with Parking Assist PARKTRONIC / System failure
If the rear view camera is not operational, the
following display appears in the multimedia system.

The following camera views are available in the
multimedia system:
Normal view
Yellow lanes marking the course
the tires
will take with the current steering angle
(dynamic)
Yellow guide line, vehicle
width (driven surface)
depending on the current steering
angle (dynamic)
Red guide line at a distance of
approximately
1...
The rear view camera will not function or will
only partially function in the following situations:
The tailgate is open.
There is heavy rain, snow or fog...
Other information:
Some systems will perform a self-test when the
ignition is switched on. Some indicator and
warning lamps may briefly light up or flash. This
behavior is non-critical. These indicator and
warning lamps indicate a malfunction only if they
light up or flash after the engine has been started
or during a journey...
Function of Active Lane Keeping Assist
Active Lane Keeping Assist monitors the area in
front of your vehicle by means of the multifunction
camera. It serves to protect
you against unintentionally leaving your lane.
You will be warned by vibration pulses in the
steering wheel and guided by a course-correcting
brake application back into your lane...