2003 Mercedes SL-Class Owner's Manual - Page 152

Controls in detail Automatic climate control Air recirculation mode Switch to air recirculation mode to prevent unpleasant odors from entering the vehicle from the outside. This setting cuts off the intake of outside air and recirculates the air in the passenger compartment. Warning! i If you keep button , pressed, the side windows will close. The air recirculation mode is activated automatically at high outside temperatures if the concentration of carbon monoxide and nitrogen oxide in the outside air increases, for example in a tunnel If you have turned off the air conditioner ( page 155) or the outside temperature is below 41°F (5°C), the air recirculation mode will not switch on automatically. Deactivating Press button , ( page 148). The indicator lamp on the button goes out. i If you keep button , pressed, the side windows will return to their previous position. The air recirculation mode is deactivated automatically after five minutes if the outside temperature is below approximately 41°F (5°C) after five minutes if the air conditioner is turned off after 30 minutes if the outside temperature is above approximately 41°F (5°C) At outside temperatures above 79°F (26°C) the system will not automatically switch back to outside air. A quantity of outside air is added after approximately 30 minutes. G When the outside temperature is below 41°F (5°C), only switch to air recirculation mode for short periods to prevent window fogging. Activating Press button , ( page 148). The indicator lamp on the button lights up. 152