2011 Mercedes GLK-Class Owner's Manual - Page 202

200 Warning and indicator lamps in the instrument cluster For your safety, we strongly recommend that you contact an authorized Mercedes-Benz Center immediately to have the system checked. Otherwise the SRS may not be activated when needed in an accident, which could result in serious or fatal injury, or it might deploy unexpectedly and unnecessarily which could also result in injury. On-board computer and displays 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 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/provinces, 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/province 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.