2005 Mercedes CLK-Class Owner's Manual - Page 204

Controls in detail Automatic climate control (CLK 500/CLK 55 AMG) Deactivating Press button , ( page 195). The indicator lamp on the button goes out. 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. Charcoal filter An activated charcoal filter markedly reduces bad odors and removes pollutants from air entering the passenger compartment. The charcoal filter can be activated or deactivated. The system switches automatically to the air recirculation mode, if the carbon monoxide (CO) 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) or nitrogen oxide (NOX) concentration of the outside air increases beyond a predetermined level. i If you keep button , pressed, the side windows and tilt/sliding sunroof* will return to their previous position. i The automatic air recirculation mode does not function if the ACOFF (indicator lamp on button ° illuminated) mode is activated or A/C (indicator lamp on button 2 not lit) mode is deactivated, or if the outside temperature has fallen below 41°F (5°C). 202