The vehicle has been started and is stationary.
A trailer has been detected.
The gradient is less than approximately 15%.
The boot lid is closed.
The electric parking brake is not applied.
. 
. The camera image is shown in the media display.
. Swipe left or right on the media display or touchpad to change the articulation angle. 
. The system calculates the articulation angle in such a way that the direction of the trailer at the time of activation is maintained. There is a short countersteering movement of the trailer while the vehicle is reversed, which then guides it back to the desired line. In this way, the vehicle is aligned straight with the trailer and, at the same time, the direction of the trailer is maintained.
The maximum articulation angle depends on the length of the trailer. This is calculated by the system by driving the vehicle forwards, including cornering. Before the length of the trailer has been calculated, the maximum articulation angle is approximately 23°. The longer the trailer is, the higher the maximum articulation angle (max. approximately 60°).
Pay attention to your surroundings and be ready to brake at all times.