2005 Mercedes SL-Class Owner's Manual - Page 127

Controls in detail Lighting Turn the exterior lamp switch to position U. With the SmartKey in starter switch position 1 or the KEYLESS-GO start/stop button pressed once, only the parking lamps will switch on and off automatically. When the engine is running, the low beam headlamps, the tail and parking lamps, the license plate lamps, and the side marker lamps will switch on and off automatically. Daytime running lamp mode Turn the exterior lamp switch to position M or U. When the engine is running, the low beam headlamps are switched on automatically. In low ambient light conditions, the following lamps will switch on additionally: Tail lamps Parking lamps License plate lamps Side marker lamps For nighttime driving you should turn the exterior lamp switch to position B to permit activation of the high beam headlamps. i With the daytime running lamp mode activated and the exterior lamp switch in position M, the highbeam headlamps cannot be switched on. The highbeam flasher is available at all times. i The fog lamps cannot be switched on with the exterior lamp switch in position U. To switch on the fog lamps, turn the exterior lamp switch to position B. 125