2005 Mercedes SL-Class Owner's Manual - Page 209

Controls in detail Driving systems i The cruise control switches off automatically if you step on the brake pedal you depress the parking brake pedal The cruise control also switches off automatically when the vehicle speed is below 25 mph (40 km/h) the ESP is in operation or switched off with the ESP switch ( page 83) you move the gear selector lever to position N while driving An accoustic warning sounds and the message TMP Off appears in the mutlifunction display for approximately five seconds. i Depressing the accelerator pedal does not deactivate the cruise control. After brief acceleration (e.g. for passing), the cruise control will resume the last speed set. Setting a higher speed Lift the cruise control in direction of arrow 1 ( page 206) and hold it there until the desired speed is reached. Release the cruise control lever. The new speed is set. Setting a lower speed Depress the cruise control in direction of arrow 2 ( page 206) and hold it there until the desired speed is reached. Release the cruise control lever. The new speed is set. i The last stored speed is canceled when you turn off the engine. ! Moving the gear selector lever to position N while driving also cancels cruise control. However, the gear selector lever should not be moved to position N while driving except to coast when the vehicle is in danger of skidding (e.g. on icy roads). i When you use the cruise control lever to decelerate, the brake system will automatically brake the vehicle if the engine's braking power does not brake the vehicle sufficiently. 207