Have you bought a car radio and get the message "No Signal" when the gear is in R? Then you can disable this message, your vehicle probably does not have a camera and that is why you will see this message.
To disable this notification, go to: Car Settings, About Device, Press the gear icon at the top right and enter the code 8888. Here you can adjust the factory settings. The setting for the camera must be in "Backcar Setup".