Moin together, does someone actually know how the air quality sensor of the automatic circulating air circuit works, or what exactly is measured and in what way ? ( photocell etc. !? ) With me the ventilation sometimes turns on lonely country road on recirculation air, on the other hand I already had in the city a Russian truck in front of me, which has fogged everything, and the air conditioning remained on “fresh air” … ( each with activated button )