There are two scenarios when the engine warning light comes on: the car has an engine system fault such as sensor issues, maintenance problems, fuel quality issues, poor mixture combustion, engine intake problems, turbocharging issues, exhaust problems, or anti-theft system malfunctions. When starting the car, the engine performs a self-check, but in this case, the light will turn off after the self-check is completed. If the engine warning light remains on for an extended period, promptly visit a repair station for troubleshooting. Sensor issues: Sensors include coolant temperature, crankshaft position, air flow, intake temperature, oxygen sensors, etc. When these sensors are damaged, have poor contact, or signal interruptions, the car's ECU cannot accurately obtain engine data, triggering the engine warning light. In such cases, seek professional inspection at a repair center to eliminate safety hazards. Maintenance issues: Poor engine maintenance is the most common cause of the engine warning light. Vehicles have specific maintenance cycles, and failing to adhere to them, combined with poor driving habits, increases the engine's operational burden, eventually causing the warning light to illuminate. Fuel quality issues: This refers to both fuel and engine oil. Cars typically require specific fuel grades, and engine oil can be semi-synthetic or fully synthetic. Manufacturers usually recommend which fuel grade and oil type to use. If the owner fails to comply, prolonged use can cause engine wear, triggering the warning light. Always use the recommended fuel grade and suitable engine oil. Poor mixture combustion: Faulty spark plugs, ignition coils, fuel pumps, or clogged fuel lines can lead to poor mixture combustion, resulting in engine carbon buildup or knocking. These issues are detected by the oxygen sensor and reported to the ECU, which then illuminates the warning light. Intake issues: The engine requires air for combustion, making the air filter crucial. A dirty or uncleaned air filter can obstruct airflow, potentially causing blockages and triggering the engine warning light. Turbocharging issues: Problems with the intake turbocharging system or turbocharger can also trigger the engine warning light. Common issues include turbocharger damage, accompanied by symptoms like oil leaks, excessive oil consumption, reduced power, metallic noises, or blue/black smoke from the exhaust. Exhaust issues: Faults in the rear oxygen sensor, catalytic converter, exhaust camshaft, or bearings can trigger the engine warning light. The catalytic converter is particularly prone to failure due to leaded gasoline, improper lubricant additives, physical damage, or fuel system issues. Anti-theft system: If the car's electronic anti-theft system malfunctions or doesn't match the engine ECU, it can prevent the engine from operating normally and trigger the warning light. Solutions for the engine warning light: If the car won't start when the engine warning light is on, it may be due to a faulty fuel pump or ignition components. Call for assistance immediately. If the car is drivable but experiences severe shaking or loss of acceleration, pull over safely and call for roadside assistance.
