2010 Mercedes C-Class Owner's Manual - Page 307
2010 Mercedes C-Class Manual
Page 307 highlights
What to do if ... Engine Problem ; The yellow engine malfunction indicator lamp comes on when the engine is running. Possible causes/consequences and M Solutions There may be a malfunction in Rthe Rthe Rthe 305 fuel management system ignition system emission control system which affect emissions Rsystems i Some states may by law require you to visit a workshop as soon as the engine malfunction indicator lamp comes on. Check local requirements. ; The yellow engine malfunction indicator lamp comes on when the engine is running. A loss of pressure has been detected in the fuel system. The fuel cap may not be closed properly or the fuel system may be leaky. X Check the fuel cap (Y page 222). X If it is not closed properly: Close the fuel cap. X If it is closed properly: Have the fuel system checked by an authorized Mercedes-Benz Center. There is insufficient coolant in the reservoir. If this warning lamp comes on frequently, there is a leak in the cooling system. If the coolant level is correct, the electric radiator fan may be broken. X Immediately add coolant to prevent engine from overheating (Y page 227). X Have the cooling system checked. X If the coolant temperature is below 248‡ (120†), you can continue driving to the nearest authorized Mercedes-Benz Center. X Avoid high engine loads (e.g. driving uphill) and stop-and-go driving. ? The red coolant temperature warning lamp comes on when the engine is running. Z Practical hints Such malfunctions may result in excessive emissions values and may switch the engine to limp-home (emergency operation) mode. X Have the vehicle checked as soon as possible at an authorized Mercedes-Benz Center.