2011 Mercedes C-Class Owner's Manual - Page 212

210 Warning and indicator lamps in the instrument cluster Engine Problem ; The yellow Check Engine warning lamp lights up while the engine is running. Possible causes/consequences and M Solutions There may be a malfunction, for example: Rin Rin On-board computer and displays the engine management the fuel injection system Rin the exhaust system Rin the ignition system Rthe fuel system The emission limit values may have been exceeded and the engine may be breaking in emergency mode. X Have the vehicle checked as soon as possible at a qualified specialist workshop. i In some states, you are required by law to visit a qualified specialist workshop as soon as the Check Engine warning lamp lights up. If necessary, check whether this is the case in the state you are in. 8 The fuel system pressure is too low. The fuel filler cap is not closed The yellow reserve fuel correctly or the fuel system is leaking. warning lamp flashes X Check that the fuel filler cap is correctly closed. while the engine is X If the fuel filler cap is not correctly closed: close the fuel filler running. cap. X If the fuel filler cap is closed: visit a qualified specialist workshop. 8 The amount of fuel in the tank has dropped into the reserve range. The yellow reserve fuel X Refuel at the nearest gas station. warning lamp lights up while the engine is running. ? The red coolant warning lamp lights up while the engine is running and the coolant temperature gauge is at the start of the scale. The temperature sensor for the coolant temperature gauge is faulty. The coolant temperature is no longer being monitored. There is a risk of engine damage if the coolant temperature is too high. X Pull over and stop the vehicle safely and switch off the engine, paying attention to road and traffic conditions. Do not continue driving under any circumstances. X Engage the parking brake. X Consult a qualified specialist workshop.