What is the car engine malfunction indicator light

The computerized control system, often referred to as the engine management system, consists of an on-board computer (ECU or ECM or PCM), a variety of sensors (such as the intake flow meter, crankshaft position sensor, camshaft position sensor, throttle position sensor, oxygen sensor, water temperature sensor, etc.), a variety of actuators (such as the fuel injector, the ignition coil, the electronic throttle drive motor, the idle valve, etc.), control program and other components. The system will alert the driver via a fault light on the instrument panel if it detects an engine fault, especially one affecting emissions. When the engine system is normal, the malfunction light will come on when the ignition switch is turned to the ON position, but the light will go off automatically after the engine is started. If the light does not come on when the ignition switch is turned to the ON position, or if the light remains on after the engine is started, or if the light suddenly and automatically comes on when the engine is running, this indicates that there is a malfunction in the vehicle's emission control system or engine management system. When the emission control system or engine management system of a vehicle malfunctions, the driver should immediately drive the vehicle to a nearby service station for overhaul. The repair station usually through the computer testing, can read the fault code stored in the engine control computer, and then according to the fault code to further detect the fault, so as to ensure that targeted to completely repair the fault.