2009 Mercedes CL-Class Owner's Manual - Page 441

Operation Tires and wheels Your vehicle has also been equipped with a TPMS malfunction indicator to indicate when the system is not operating properly. The TPMS malfunction indicator is combined with the low tire pressure telltale. When the system detects a malfunction, the telltale will flash for approximately 1 minute and then remain continuously illuminated. This sequence will continue upon subsequent vehicle start-ups as long as the malfunction exists. When the malfunction indicator is illuminated, the system may not be able to detect or signal low tire pressure as intended. TPMS malfunctions may occur for a variety of reasons, including the installation of replacement or alternate tires or wheels on the vehicle that prevent the TPMS from functioning properly. Always check the TPMS malfunction telltale after replacing one or more tires or wheels on your vehicle to ensure that the replacement or alternate tires and wheels allow the TPMS to continue to function properly. 10 minutes for the system to signal a malfunction using the TPMS telltale flashing and illumination sequence. The telltale extinguishes after a few minutes driving if the malfunction has been corrected. Tire pressure inquiries are made using the multifunction display. The current tire inflation pressure for each tire appears in the multifunction display after a few minutes of driving. X Press button $ or% to select Tire Press.. X Press button #. The current inflation pressure for each tire appears in the multifunction display. i Possible differences between the readings of a tire pressure gauge of an air hose, e.g. gas station equipment, and the vehicle's control system can occur. The tire pressure displayed by the control system apply to sea level. In high-altitude locations, the reading on a tire pressure gauge will be higher than the reading issued by the vehicle's control system. Do not reduce the tire inflation pressure under such circumstances. X X When the vehicle has been parked for longer than 20 minutes, the message Tire Pressure Displayed After Driving A Few Minutes appears in the multifunction display. i USA only: If a condition causing the TPMS to malfunction develops, it may take up to Switch on the ignition. Press button ( or & on the multifunction steering wheel to select the Service menu (Y page 245). i With a spare wheel mounted, the system may still indicate the tire inflation pressure of the removed road wheel for some minutes. If this happens, keep in mind that the indicated value where the spare wheel is mounted does not reflect the actual spare tire inflation pressure. i Operating radio transmission equipment (e.g. wireless headsets, two-way radios) in Z 439