2011 Mercedes SL-Class Owner's Manual - Page 149

Driving systems segment illuminates and a constant acoustic warning lasting a maximum of 2 seconds will sound for the second red distance segment. The signal is canceled when the automatic transmission is shifted into park position P or the parking brake is engaged. RRear 147 Parktronic system malfunction There is a malfunction in the Parktronic system, if only the red distance segments illuminate and an acoustic warning sounds. The Parktronic system will switch off automatically after 20 seconds and indicator lamp ; in Parktronic switch : comes on. X area: An intermittent acoustic warning will sound when the first distance segment illuminates. This signal quickens with each additional distance segment lit. When the eighth distance segment illuminates, the acoustic warning becomes a constant signal. The signal is canceled when the automatic transmission is shifted into drive position D, or park position P, or the parking brake is engaged. Switching the Parktronic system on/ off The Parktronic system switches on automatically when the ignition is switched on. Have the Parktronic system checked at an authorized Mercedes-Benz Center as soon as possible. If only the red distance segments illuminate and no acoustic warning sounds, the Parktronic system sensors are dirty (e.g. dirt, ice, snow and slush). Another cause could be interference from other radio or ultrasonic signals (e.g. truck air brakes, car wash, or jackhammers). The Parktronic system will switch off automatically after 20 seconds and indicator lamp ; in Parktronic switch : comes on. X Switch off the ignition. X Clean the Parktronic system sensors (Y page 218). X Switch on the ignition. or X Check the Parktronic system operation at another location to rule out interference from outside radio or ultrasonic signals. X Switching off: Press Parktronic switch :. Indicator lamp ; comes on. X Switching on: Press Parktronic switch : again. Z Controls in detail