The system is activated automatically approximately one second after you engage reverse gear or move the AT control lever to position R, if the ignition key is in position 2. If you disengage reverse gear, the PDC system will also be deactivated. If you are driving with the sight, the system cannot perform its functions, and therefore it is deactivated in this case.
Sound signals
When the distance to the object behind is dangerously reduced, a periodic sound signal is emitted. As the distance gets closer, the frequency of the signal increases, and when the distance to the obstacle is less than 30 cm, the sound becomes continuous.
The signaling stops after three seconds if the vehicle is moving (for example, parallel to the wall) there is no approach to the obstacle.
A fault in the system is indicated by a continuous high-pitched signal that sounds when the system is first switched on. In this case, contact a BMW service centre to have the fault rectified. The presence of the PDC system does not relieve the driver of the responsibility for independently assessing the distance to obstacles. Objects that fall into the blind spot of the sensors are not detected by the system and do not trigger the alarm. Object recognition may also go beyond the limits of what is physically possible with ultrasonic measurements, for example with the drawbar and trailer coupling, as well as thin objects and painted surfaces.
To ensure that the sensors remain fully functional, they should be kept clean and free of ice.
Avoid exposing the sensors to steam jets for long periods of time (the distance should not be less than 10 m).