Function

Function
The automatic air conditioning (auto A/C) has an electronically and pneumatically controlled cooling, heating and ventilation system and can be summarized with the partial functions described below.

- Ventilation
The ventilation provides for the air flow through the passenger compartment. The air flow is supported by the automatic A/C blower or the rear A/C blower in normal operation when the vehicle is standing still or to increase the quantity of air. The air is distributed in the vehicle passenger compartment by the air distribution flaps.

- Automatic A/C pushbutton control module
The automatic A/C can be controlled by the driver with the various function buttons. In addition the pushbutton control module reads in the signals from various sensors, processes the signals and controls the components in the automatic A/C system.

- Automatic A/C temperature control
The desired temperature is achieved or maintained by cooling or heating the air. Precise temperature control is achieved by reading in various temperature sensors.

- Heater circuit
The coolant is heated by the engine. Then the heated coolant flows through the heater core where the heat is transferred to the passenger compartment air. The coolant returns to the coolant pump through the heater return line.

- Refrigerant circuit
The A/C compressor compresses the gaseous refrigerant, which heats up and flows into the condenser where it is cooled. After purification in the receiver, the liquid refrigerant is sprayed into the evaporator The refrigerant evaporates and cools down. The A/C compressor sucks in the refrigerant which has again become gaseous due to the heat absorbed.

- Residual engine heat utilization system
The residual engine heat utilization system makes it possible to heat the vehicle even with the ignition OFF. The system uses the residual engine heat for this purpose and transfers it into the vehicle passenger compartment with the blower.