The air quality sensor is part of the air conditioning system. It measures pollutants, in the form of oxidisable or reducible gases, in the air outside your car. Oxidisable gases include carbon monoxide, hydrocarbons (vapours from benzene or petrol) and other partially burnt fuel components. If the quality of the outside air drops, the control system activates the Climatronic air recirculation mode, stopping polluted air from coming in and maintaining the quality of air inside the car.
