2003 Mercedes C-Class Owner's Manual - Page 110

Controls in detail Instrument cluster Outside temperature indicator Warning! The temperature sensor is located in the front bumper area. Due to its location, the sensor can be affected by road or engine heat during idling or slow driving. This means that the accuracy of the displayed temperature can only be verified by comparison to a thermometer placed next to the sensor, not by comparison to external displays (e.g. bank signs etc.). When moving the vehicle into colder ambient temperatures (e.g. when leaving your garage), you will notice a delay before the lower temperature is displayed. A delay also occurs when ambient temperatures rise. This prevents inaccurate temperature indications caused by heat radiated from the engine during idling or slow driving. G The outside temperature indicator is not designed to serve as an ice-warning device and is therefore unsuitable for that purpose. Indicated temperatures just above the freezing point do not guarantee that the road surface is free of ice. The road may still be icy, especially in wooded areas or on bridges. 110