2399243 - E3030 HEATED REAR WINDSCREEN AND DOOR MIRROR DEFROSTING - Description (Low setup)

Description

In the case of poor visibility, it is possible to activate demisting of the rear window and the door mirrors.

The heating resistances for these components absorb a considerable amount of energy and they are therefore checked and deactivated after a certain period: the defrosting is timed, according to the following logic, managed by the Body Computer:

• ignition ON (INT/A);
• activation signal from the relevant button, located on the climate control system control panel.

In these circumstances the resistances remain supplied for a maximum of 20 minutes, then the power supply is cut off.

The power supply is also cut off under the following conditions:

• ignition in OFF position;
• deactivation signal from the relevant button;
• battery voltage below 8.5 V
• after the first 10 minutes operation, if the engine speed is below 960 rpm.

When the demister is on, a warning light on the climate control system control unit is activated.The timed activation (20 minutes) is restored each time the button is operated.

Description

The control logic for the climate control system control unit also intervenes for the MAX DEF control in accordance with the logic described previously.The action of the MAX DEF function last 3 minutes starting from when the temperature of the engine exceeds a certain limit.

deactivating the MAX-DEF control only causes the heated rear windscreen to switch off if the command to switch on was given by MAX-DEF; if, on the other hand, the command came from the heated rear windscreen button, it remains on.

Description

The rear window demisting circuit is controlled by the heated rear windscreen relay and is protected by two fuses, one for the rearscreen and the other for the other resistances, all housed in the underdashboard junction unit. This circuit is controlled via the strategy described above directly from the Body Computer.