The parking assistance system provides the driver with information, whilst reversing, on the distance from any objects behind the vehicle which could be out of their range of view.The information of the presence/distance of an obstacle is transmitted to the driver by means of acoustic warnings whose frequency depends on the distance of the vehicle from the obstacle.An electronic control unit activates and controls the operation of the sensors located in the rear bumper, processes the signals received and operates the buzzer in the instrument panel.The system is activated with reverse gear engaged: in these conditions, the control unit energizes the transducers and sends them a signal request, receiving the response signals.The sensors use ultrasound technology and act as intelligent transmitters/receivers with triangulation technology: allowing improved detection in critical situations or in the presence of small obstacles. The impulses emitted are reflected by any obstacles; the transducer receives an echo which is converted into a digital signal and sent to the electronic control unit.The signalling of the distance of the obstacle is achieved through intermittent impulse sound signals: the frequency of this signal increases gradually as the bumper approaches an obstacle: when the distance calculated goes below 30 cm, the sound becomes high pitched and constant; the acoustic signal stops when the distance of the obstacle increases.For more details and information on the operation of the system, See descriptions 5580H PARKING OBSTACLE DETECTION DEVICEThe control unit is equipped with an autodiagnostic function: when switched on the control unit carries out an initial test on the sensors which are then continuously subject to fault diagnosis during the operation of the system.A fault in only one sensor inhibits the operation of the entire system: in this case the system excludes itself and sends a fault message, the failure status is signalled to the instrument panel which lights up the special warning light and sends a suitable acoustic signal.The signal that the reversing light has come on See E2022 REVERSING LIGHTSis managed by the Body Computer which forwards this information via the CAN to the parking sensors control unit.If there is a trailer then there is no signalling of rear obstacles. See E2050 TRAILER WIRINGThe system is supplied by the circuit protected by a specific fuse in the junction unit under the dashboard.