In the event of poor visibility it is possible to activate the defrosting of the rear windows, the door mirrors and the screen washer jets.

The heating coils for these components absorb a considerable amount of energy and are therefore controlled and deactivated after they have been working for a certain length of time: the defrosting is subject to a delay timer, managed by the Body Computer, according to the following logic:

- ignition-operated, starting excluded (INT/A);

- engagement signal coming from the special button in the middle of the dashboard.

Under these circumstances the heating coils remain supplied for a maximum of 20 minutes, then the supply is cut off.

The supply is cut off in the following conditions:

- key-off;

- disengagement signal from the button;

- battery voltage below 11.5 V;

- after the first 10 minutes of operation if the engine speed is below 960 rpm.

With the defrosting on, the warning light next to the control button also comes on.

The activation timer (20 minutes) is set again each time the button is operated.

On versions with an AUTOMATIC AIR CONDITIONER, the climate control system control unit logic also intervenes with the "MAX-DEF" command.

deactivation of the MAX-DEF control only causes the switching off of the heated rear window 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 window button, it remains on

The defrosting circuit for the rear window, the door mirrors and the screen washer jets is controlled by a dedicated relay switch and protected by a dedicated fuse located in the engine compartment junction unit.

The heated rear window relay switch T19, located in the engine compartment junction unit B001, controls the engagement of the rear window defrosting coils P055 via the line protected by fuse F20 of junction unit B001.

The same heated rear window relay switch T19 controls the engagement of the defrosting coils for the door mirrors P060 and P061 and for the screen washer jets O050 and O051 via the line protected by fuse F87 of control unit B001.

The coil of relay switch T19 receives an ignition-operated (INT) power supply protected by fuse F51 of M001.

Relay switch T19, on the other hand, is energised by an earth signal coming from the Body Computer M001 - pin 6 of connector B; this signal is sent on the basis of the control logic illustrated previously and in the presence of the defrosting command:

- on versions with MANUAL AIR CONDITIONING from pin 10 of the switch in unit H080 to pin 41 of connector D of M001; with the coils on, the Body Computer M001 sends the positive signal to turn on the LED next to the actual button from pin 21 of connector B.

- on versions with AUTOMATIC AIR CONDITIONING, the engagement request, the MAX DEF function and the feedback signal with the coils on are exchanged via the CAN line.

The Body Computer M001 - connector A - receives a direct power supply from the battery through the line protected by maxi fuse F01 of the engine compartment junction unit B001.

The Body Computer M001 receives an ignition-operated (INT) power supply at pin 11 of connector E, whilst the ignition-operated (INT/A) signal reaches pin 1 of connector E.

Pin 9 of connector E of M001 provides the Body Computer with a reference earth.