Air Conditioning (Tempmatic), Function

Function
The electronically controlled air conditioning, heating and ventilation system of the Tempmatic A/C maintains the desired passenger compartment temperature at a constant level.

Beginning with blower stage 1 the air conditioning is switched on each time the engine is started operating according to the so- called "reheat" principle.
This means:

The A/C compressor always runs when the outdoor temperature is higher than 1 °C cooling the already cold incoming air. This effect serves primarily for comfort because when the air is cooled it is simultaneously dried which is an important prerequisite for a pleasant interior atmosphere. Following the cooling process the dried air is heated to the desired temperature by the heater core. The air conditioning can be switched off with the EC button.

Heating mode
The heater core temperature sensor measures the air temperature at the heater core while the outdoor air temperature sensor measures the temperature of the outdoor air.

The electronic circuitry in the push-button control module compares the various values with the desired temperature set on the temperature dials.
The electronic control readjusts the heater or maintains the settings depending on the requirement.

Air conditioning mode
The evaporator temperature sensor measures the temperature at the evaporator air outlet while the outdoor air temperature sensor measures the temperature of the outdoor air.

The electronic circuitry in the push-button control module compares the desired temperature set on the temperature dials with the outdoor temperature and regulates the outlet temperature using a curve stored in the push-button control module.

The electronic control readjusts the settings or maintains them as required.