There are primarily 7 reasons for the engine warning light to illuminate: Sensor malfunction: This refers to sensors including coolant temperature, crankshaft position, air flow, intake temperature, and oxygen sensors. When these sensors are damaged, have poor connections, or experience signal interruptions, the vehicle's ECU cannot accurately obtain engine data, triggering the engine warning light. Fuel quality issues: Failure to use the fuel and engine oil as specified by the manufacturer may cause engine wear, leading to the illumination of the warning light. Poor combustion of the air-fuel mixture: This can result in engine carbon buildup or knocking. When detected by the oxygen sensor and reported to the ECU, the warning light will illuminate as an alert. Spark plug failure, ignition coil failure, fuel pump failure, and fuel line blockages can all cause poor combustion of the air-fuel mixture. Turbocharging issues: The intake turbocharging pipeline and turbocharger can also trigger the engine warning light. The most common issue is turbocharger damage, accompanied by symptoms such as oil leaks, excessive oil consumption, reduced power, metallic noises, and blue or black smoke from the exhaust. Intake issues: Problems with the car's intake system can lead to engine pipeline blockages, and in severe cases, trigger the engine warning light. A dirty air filter that is not cleaned regularly can cause intake problems. Exhaust issues: Exhaust system malfunctions can also cause the engine warning light to illuminate. Common causes include faults in the rear oxygen sensor, catalytic converter, exhaust camshaft, and bearing shells, with the catalytic converter being the most frequent issue. Using leaded gasoline, lead or silicon-based lubricant additives, physical damage to the catalytic converter, or faults in the engine fuel supply system can easily lead to catalytic converter failure. Anti-theft system malfunction: If the car's electronic anti-theft system fails, or if the anti-theft controller does not match the engine electronic controller, the anti-theft system can prevent the engine from operating normally and trigger the engine warning light. If the engine warning light is on, follow these steps: First, check if the engine is running normally, looking for issues such as shaking or black smoke. If present, avoid restarting the engine. Note: Do not restart the engine if the red warning light is on. If the engine can be started, turn it off and wait 5-10 minutes. Without pressing the brake, press the start button once or turn the key halfway to the 'on' position without pressing the clutch. The car will perform a self-check upon powering up. After 5-10 seconds, observe whether the warning light on the dashboard turns off. If the warning light remains on, visit a service station as soon as possible. The service station can use a portable diagnostic tool to read the fault code, identify the issue, and perform targeted repairs.
