2001 Mercedes C-Class Owner's Manual - Page 277

Instruments and controls Operation Driving Instrument cluster display Practical hints Car care Technical data Index Malfunction and indicator lamps Malfunction and indicator lamps in the instrument cluster General information: If a bulb in the instrument cluster fails to light up during the bulb self-check when turning the electronic key in steering lock to position 2, have it checked and replaced if necessary. Emission control Certain systems of the engine serve to keep the toxic components of the exhaust gases within permissible limits required by law. These systems, of course, will function properly only when maintained strictly according to factory specifications. Any adjustments on the engine should, therefore, be carried out only by authorized Mercedes-Benz Center qualified technicians. Engine adjustments should not be altered in any way. Moreover, the specified service jobs must be carried out regularly according to Mercedes-Benz servicing requirements. For details refer to the Service Booklet. 268 Warning! Inhalation of exhaust gas is hazardous to your health. All exhaust gas contains carbon monoxide, and inhaling it can cause unconsciousness and lead to death. Do not run the engine in confined areas (such as a garage) which are not properly ventilated. If you think that exhaust gas fumes are entering the vehicle while driving, have the cause determined and corrected immediately. If you must drive under these conditions, drive only with at least one window fully open. On-board diagnostic system Check engine malfunction indicator lamp Engine malfunction indicator lamp. If the "CHECK ENGINE" malfunction indicator lamp comes on when the engine is running, it indicates a malfunction of the fuel management system, emission control system, systems which impact emissions, or the fuel cap is not closed tight (check the fuel cap). If the "CHECK ENGINE" lamp is illuminated continuously and the vehicle is driving normally, you