The regulating element for the automatic window defrosting/defogging is control wheel integrated in the control unit/operating unit with 5 discrete positions. It enables the settings: OFF, LOW, MED, HIGH and DEF.
In the OFF position, the defrosting flaps are closed. The blower voltage is reduced to the value without the share for the windows.
So as not to influence the air volume distribution at the air vents, the blower must be raised or lowered with respect to the position LOW, MED and HIGH by a fixed value. This fixed blower speed increase is stored for all three positions in the control unit.
The DEFROST function is switched on and off via the DEF position of the control wheel for the automatic window defrosting/defogging. On activation of the DEFROST function, fresh-air mode is activated. After subsequent deactivation, the fresh-air mode is only maintained for approx. 5 minutes.
In order to avoid starting condensation, the defrosting flaps remain closed 12 seconds after the engine is started.
After the DEFROST, the defrosting flaps are moved with a delay into the new flap position.