312000947 - E3030 REAR SCREEN AND REAR VIEW MIRROR DEMISTING - DESCRIPTION

DESCRIPTION

In the case of poor visibility it is possible to activate the demisting of the rear screen and the door mirrors (if present).The heating resistances for these components absorb a considerable amount of energy and are therefore controlled and deactivated after a certain period of operation; the defrosting is timed according to a logic managed by the Body Computer:

  • excluded during starting (INT/A);
  • by the on signal coming from the dedicated button located in the panel near the heating/climate control system controls;
  • on versions with AUTOMATIC AIR CONDITIONING, by the on signal for the MAX-DEF button in the control panel.
Under these circumstances the resistances remain supplied for a maximum of 20 minutes, then the supply is cut off.The supply is cut off in the following conditions:

  • at the key off (key OFF or extracted);
  • via the disengagement signal from the dedicated button;
  • with the battery voltage below 11.5 V;
  • after the first 10 minutes of operation if the engine speed is below 960 rpm.
During the first ten minutes of operation, defrosting is guaranteed irrespective of the engine speed.With the defrosting on the LED in the control panel comes on.The activation timer (20 minutes) is set again each time the button is operated.In specifications with an AUTOMATIC AIR CONDITIONER, the climate control system control unit logic also intervenes with the "MAX-DEF" command in accordance with the logic described previously.The "MAX-DEF" function lasts for 3 minutes starting from when the engine temperature exceeds a certain limit.
The deactivation of the MAX-DEF control only causes the switching off of the heated rear windscreen if the command to switch it on came from the MAX-DEF button; if, on the other hand, the command was given via the heated rear windscreen button, it remains on.
The defrosting circuit for the rear windscreen and the exterior rear view mirrors (if present) is operated and protected by a relay and a fuse respectively located in the engine compartment junction unit; the defrosting circuit for the rear view mirrors also has another fuse located near the diagnostic socket. This circuit is controlled by the logic described above directly by the Body Computer.On versions with AUTOMATIC AIR CONDITIONING, the control signal, on the other hand, reaches the Body Computer from the climate control system control unit via the B-CAN.
On versions with a manually operated air conditioner and heater, the defrosting can only be activated using the dedicated button.