2427966 - E3030 HEATED REAR WINDSCREEN AND DOOR MIRROR DEFROSTING - Description (High setup)

Description

In the case of poor visibility, it is possible to activate demisting of the rear windscreen 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 1000 rpm.
When the demister is on, a warning light on the climate control system controls is activated.

The climate control system ECU strategy is also operational in the following situations:

  • 'MAX-DEF' command from the climate control: the defrosting function is activated using the logic described previously (deactivating the MAX-DEF control only causes the heated rear windscreen to be switched off if the command to turn it on came from the MAX-DEF; if, on the other hand, the command came from the heated rear windscreen button, it remains on;
  • automatic defrosting at low outside temperatures: the heated rear windscreen is switched on automatically if the outside temperature, detected by the climate control system control unit via the special sensor, is below 3 °C.
The rearscreen demisting circuit is controlled by the heated rear windscreen relay and protected by a special fuse located in the junction unit under the dashboard. This circuit is controlled via the strategy described above directly from the Body Computer.The door mirror demisting circuit for is protected by another fuse in the underfacia control unit and is controlled by the door control unit in accordance with a strategy transmitted via the CAN network from the Body Computer.