System-related characteristics

Despite the PDC, it is still the responsibility of the driver particularly to assess obstructions wherever detection of objects approaches the physical limits of ultrasonic measurement.

System-related problems may arise even under optimum preconditions. It is possible that a non-existent obstruction is signalled or an existing obstruction is not signalled.

In the following situations it is possible that the PDC signals an obstruction although one does not exist:

• heavy rain
  
• sensors extremely dirty, iced up or covered with snow
  
• ground echoes from rough road surfaces, grass
  
• in large closed rectangular rooms with smooth walls (e.g. underground car parks)
  
• if the sensors are not fitted correctly in their holders, heavily soiled or iced up
  

In the following situations it is possible that the PDC does not signal an obstruction:

• low objects with corners and sharp edges
  
• when driving beside a wall while parking, the acoustic signal is switched off for this duration even if the vehicle approaches an obstruction at a different angle, although further away.
  
• when the obstruction is located precisely between two sensors