2011 Mercedes R-Class Owner's Manual - Page 244

242 Warning and indicator lamps in the instrument cluster Engine Problem Possible causes/consequences and M Solutions On-board computer and displays ! (USA only) There may be a malfunction, for example: ; (Canada only) Rin the engine management Rin the fuel injection system The yellow engine diagnostics warning Rin the exhaust system lamp lights up while the R in the ignition system (for vehicles with gasoline engines) engine is running. 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 to visit a qualified specialist workshop as soon as the yellow engine diagnostics warning lamp lights up due to the relevant applicable legislation. If necessary, check whether this is the case in the state you are in. ! (USA only) The fuel system pressure is too low. The fuel filler cap is not closed correctly or the fuel system is leaking. ; (Canada only) X Check that the fuel filler cap is correctly closed. The yellow engine X If the fuel filler cap is not correctly closed: close the fuel filler diagnostics warning lamp lights up while the cap. engine is running. X If the fuel filler cap is closed: visit a qualified specialist workshop. Vehicles with a diesel engine: the fuel tank has been run completely dry and the engine will not start. There is air in the fuel system (Y page 164). The yellow reserve fuel The fuel level has fallen below the reserve range. warning lamp lights up The fuel tank must be filled at least to the reserve fuel level to while the engine is prevent impairment to the running of the engine. running. X Refuel at the nearest gas station.