The system is activated automatically approximately one second after reverse gear is engaged or the AT control lever is moved to position R, if the ignition key is in position 2. If you disengage reverse gear, the PDC system will also turn off. If you move with a sight, the system cannot perform its functions, and therefore it is turned off in this case.
Sound signals
When the distance to the object behind is dangerously reduced, a periodic sound signal is given. As you get closer, the frequency of the signal increases, and when there is less than 30 cm to the obstacle, the sound becomes continuous.
Signaling stops after three seconds if the vehicle is moving (e.g. parallel to the wall) there is no approach to the obstacle.
A malfunction in the system is indicated by a continuous high tone sounding when the system is first turned on. In this case, contact a BMW workshop for troubleshooting. The presence of a PDC system does not release the driver from the responsibility for self-assessment of distances to obstacles. Objects that fall into the dead zone of the sensors are not recognized by the system and do not trigger an alarm. Object recognition can also go beyond what is physically possible with ultrasonic measurements, for example with drawbars and trailer hitches, as well as thin objects and varnished surfaces.
To maintain the full functionality of the sensors, they should be kept clean and de-iced.
It is unacceptable to hit the sensors with jets of steam for a long time (the distance should not be less than 10 m).