The relay F17 for the engine compartment junction unit B001 is supplied directly by the battery from the line protected by fuse F9 (also located inside junction unit B001) and is energized by the line controlled by the ignition INT/A via fuse F31 in the junction unit under the dashboard B002.When the Body Computer receives an activation command from the steering column switch unit H005 (pin 5 of connector A) at pin 13 of connector A, having already received a command to switch on the dipped headlamps (pin 4 of connector E) or the main beam headlamps (pin 33 of connector C), it sends a negative signal, from pin 14 of the same connector, to control the coil for relay R17 which supplies the headlamp washer pump interfaced with the front/headlamp washer coupling D098 at pin 5.If there is insufficient windscreen washer fluid in the reservoir, then the info-telematic control unit M065 receives a negative signal, at pin 21 of connector A, from the switch interfaced with the front/headlamp washer coupling D098 (pin 2); this signal is sent via the B-CAN (pins 1 and 3 of connector A) to the instrument panel E050 (pins 3 and 4 of connector A) which displays the message.