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

Controls in detail Climate control Deactivating Press button P. The indicator lamp on the button goes out. Defrosting is turned off. 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! Activating Press button O. The indicator lamp on the button comes on. i If you keep button O pressed the side windows and sliding/pop-up roof* will be returned 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 conditioning 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. i If you keep button O pressed the side windows and sliding/pop-up roof* will be closed. The air recirculation mode is activated automatically at high outside temperatures. If you have turned off the air conditioning ( page 154) or the outside temperature is below 41°F (5°C), the air recirculation mode will not switch on automatically. Deactivating Press button O. The indicator lamp on the button goes out. G When the outside temperature is below 41°F (5°C), only switch to air recirculation mode for short periods to prevent window fogging. 152