2007 Mercedes S-Class Owner's Manual - Page 516

Operation Tires and wheels Press #. The message Tire pressure monitor reactivated appears in the multifunction display. After a few minutes driving, the current tire inflation pressure values are accepted as reference values and then monitored. If you wish to cancel activation: Press L. or Press $ to exit menu screen. Run Flat Indicator (Canada only) While the vehicle is being driven, the Run Flat Indicator monitors the set tire inflation pressures by evaluating each wheel's rotational speed. This allows the system to detect a significant loss of pressure in a tire. If a wheel's rotational speed changes due to falling tire inflation pressure, you will see a corresponding warning message in the multifunction display. The Run Flat Indicator may function in a restricted manner or with a delay if: snow chains are mounted to the vehicle in presence of ice and snow you are driving on a loose surface (e.g. sand or gravel) you are driving in a very sporty manner (involving rapid acceleration or high speeds in curves) Warning! G i When the wheel positions are changed on the vehicle, it is possible that the air pressure is temporarily displayed for the wrong position. This will be corrected after driving for several minutes, and the air pressure will be shown for the correct position. When the multifunction display shows the message "Tire pressure Check tires", one or more of your tires is significantly under-inflated. You should stop and check your tires as soon as possible, and inflate them to the proper tire inflation pressure as indicated on the vehicle's tire information placard. Driving on a significantly underinflated tire causes the tire to overheat and can lead to tire failure. Under-inflation also reduces fuel efficiency and tire tread life, and may affect the vehicle's handling and stopping ability. Each tire, including the spare, should be checked monthly when cold and set to the tire inflation pressure recommended by the vehicle manufacturer on the vehicle placard or the tire inflation pressure label. 515