2007 Mercedes GL-Class Owner's Manual - Page 292

Controls in detail Driving systems The Parktronic system deactivates at vehicle speeds exceeding approximately 11 mph (18 km/h). At lower vehicle speeds the Parktronic system turns on again. The Parktronic system also deactivates when you set the automatic transmission to position P or depress the parking brake pedal. The Parktronic system monitors the surroundings of your vehicle with six sensors in the front bumper and four sensors in the rear bumper. Range of the sensors To function properly, the sensors must be free of dirt, ice, snow and slush. Clean the sensors regularly, being careful not to scratch or damaging the sensors, see "Cleaning the Parktronic* system sensors" ( page 430). ! During parking maneuvers, pay special attention to objects located above or below the height of the sensors (e.g. planters or trailer hitches). The Parktronic system will not detect such objects at close range and damage to your vehicle or the object may result. Ultrasonic signals from outside sources (e.g. working jackhammers, car wash or the air brakes of trucks) may impair the operation of the Parktronic system. 1 Sensors in the front bumper 291