Air RECIRCULATION Mode Function

The air recirculation mode function encompasses the following functions:

• Air recirculation mode using air intake switch function
• Pollutant-sensitive air recirculation mode function

Air Recirculation Mode Using Intake Switch Function 

When the intake switch on the A/C control is pressed for less than 1.5 seconds, the intake door is closed to prevent air entering from outside. The air only circulates in the vehicle interior and unpleasant odors and harmful gases are kept out. The indicator lamp above the intake switch lights up during air recirculation mode.

The A/C auto amp. reads in the status of the intake switch directly and actuates the intake door motor via climate control LIN.

Pollutant-sensitive Air Recirculation Mode Function 

Function Requirements for pollutant-sensitive air recirculation mode

• Compressor switched ON
• Defrost mode not active

Function Sequence for Pollutant-sensitive air recirculation mode

• The air quality sensor records the pollutant levels of the outside air.

  The A/C auto amp. reads in the signals of the air quality sensor via climate control LIN. As of a certain pollutant concentration, the intake door is automatically set to the recirculated air position by the intake door motor. Outside air supply is prevented and only the inside air is recirculated.

  If the conditions for the pollutant-controlled air recirculation mode exist after the engine is started, a supply of fresh air is first provided for 30 seconds. Following this, operation continues first with 80% pollutant-controlled recirculated air and after another 10 seconds, as required, with 100% pollutant-controlled recirculated air. The pollutant-controlled air recirculation mode is not indicated by the indicator lamp in the intake switch.