Function

Function

Air conditioning
See: Air conditioning Air Conditioning

Air distribution system
See: Air distribution system Air Distribution System

Blower fan




The blower fan provides the airflow through the vehicle.
The blower fan must be operating before the climate control system can be engaged.
The blower fan switches off when the vehicle speed is approximately 160 km/h.

Filter




The particle filter cleans the air of particles such as dust and pollen, which would otherwise pass through the air intake into the passenger compartment.
The multi-filter has the same function as the particle filter, but also neutralizes unpleasant smells and keeps the air as free from gases as possible. In vehicles that have the multi-filter, known as the air quality system (AQS), there is also an outside air sensor that ensures that the recirculation closes in the event that the content of gases in the outside air increases. This increases the service life of the multi-filter.

Additional heater/Parking heater




The additional heater/parking heater produces heat by burning gasoline or diesel. The heat is distributed via the engine cooling system to the heat exchanger and on out into passenger compartment.
When the engine is running, the additional heater can provide extra heat to the passenger compartment in the event that the engine is unable to provide sufficient heat. When the engine is not running, the parking heater can heat the passenger compartment (and the engine). This function can be started directly or using a timer.
For further information about the additional heater/parking heater, see Design and Function, Additional and parking heater (combustion preheater module (CPM)).