2006 Mercedes CLK-Class Owner's Manual - Page 204

Controls in detail Automatic climate control (CLK 500/CLK 55 AMG) Air recirculation mode Switch to air recirculation mode to prevent unpleasant odors from entering the vehicle from the outside (e.g. before driving through a tunnel). This setting cuts off the intake of outside air and recirculates the air in the passenger compartment. Warning! Activating Press button , ( page 197). The indicator lamp on the button comes on. Warning! G i The air recirculation mode is activated automatically at high outside temperatures. The indicator lamp on the button , is not lit when the air recirculation mode is automatically switched on. A quantity of outside air is added after approximately 30 minutes. Never operate the side windows if there is the possibility of anyone being harmed by the closing procedure. In the event that the procedure causes potential danger, the closing of the side windows can be immediately halted by releasing the , button or by pressing or pulling the respective window switch. G Fogged windows impair visibility, endangering you and others. If the windows begin to fog on the inside, switching off the air recirculation mode immediately should clear interior window fogging. If interior window fogging persists, make sure the air conditioning ( page 206) is activated, or press button P or 0. i If you press and hold button ,, the side windows will close. 203