2008 Mercedes R-Class Owner's Manual - Page 282

Controls in detail Driving systems Permanent four-wheel drive (4MATIC)* Your vehicle is equipped with permanent four-wheel drive (4MATIC). Both, the front and rear axles, are powered at all times when the vehicle is being operated. The 4MATIC improves traction in conjunction with the ESP® ( page 101) and the Electronic Traction System ( page 103). Warning! ! Operational or performance test must only be conducted on a two-axle dynamometer. If such tests are necessary, contact an authorized Mercedes-Benz Light Truck Center. You could otherwise seriously damage the brake system or the transfer case which is not covered by the Mercedes-Benz Limited Warranty. ! Because the ESP® operates automatically, the engine and ignition must be shut off (SmartKey in starter switch position 0 or 1 or KEYLESS-GO* start/stop button in position 0 or 1) when testing the parking brake on a brake test dynamometer and such testing should be no longer than 10 seconds. Active braking action through the ESP® may otherwise seriously damage the brake system which is not covered by the Mercedes-Benz Limited Warranty. Parktronic* (Parking assist) Warning! G Parktronic is a supplemental system. It is not intended to, nor does it replace, the need for extreme care. The responsibility during parking and other critical maneuvers always remains with the driver. Special attention must be paid to objects with smooth surfaces or low silhouettes (e.g. trailer couplings, painted posts, or road curbs). Such objects may not be detected by the system and can damage the vehicle. The operational function of the Parktronic system can be affected by dirty sensors, especially at times of snow and ice, see "Cleaning the Parktronic* system sensors" ( page 408). Interference caused by other ultrasonic signals (e.g. working jackhammers, car wash, or the air brakes of trucks) can cause the system to send erratic indications, and should be taken into consideration. G If a drive wheel is spinning due to insufficient traction: While driving off, apply as little throttle as possible. While driving, ease up on the accelerator. Adapt your speed and driving style to the prevailing road conditions. Failure to observe these guidelines could cause the vehicle to skid. The 4MATIC cannot prevent accidents resulting from excessive speed. i In winter operation, the maximum effectiveness of the 4MATIC is only achieved with winter tires ( page 398) or snow chains as required. 281