See also:

Malfunction
A Check Control message is displayed. The parking assistant failed. Have the system checked. ...

System limits
Check the traffic situation as well PDC cannot serve as a substitute for the driver's personal judgment of the traffic situation. Check the traffic situation around the vehicle with your own ey ...

Condensation under the parked vehicle
When using the automatic climate control, condensation water develops that exits underneath the vehicle. Therefore, traces of condensed water under the vehicle are normal. ...