What is the cause of Mercedes-Benz engine fault light?

What is the cause of Mercedes-Benz engine fault light? What is the cause of Mercedes-Benz engine fault light? The causes of the failure light of Mercedes-Benz engine are as follows: 1, poor oil quality:, and the fuel quality used by motor vehicles is not very good, so it is necessary to refuel at a regular gas station. 2. Engine carbon deposit: There is some carbon deposit in the engine, which is located in the throttle, spark plug, fuel injector and air intake. Sensor failure: The engine water temperature sensor fails, and the engine cannot sense the water temperature. When the motor vehicle engine fault light is on, it means that the motor vehicle engine has a fault and needs to be checked and repaired in time. After maintenance, the engine fault light will be eliminated. @20 19