There are mainly 7 reasons why the engine malfunction light is on: Sensor malfunction: The sensors mentioned here include coolant temperature, crankshaft position, air flow, intake air temperature, oxygen sensors, etc. When these sensors are damaged, have poor contact, or signal interruption, the car's ECU cannot accurately obtain engine data, which will trigger the engine malfunction light. Fuel quality issues: If fuel and engine oil are not added according to the manufacturer's requirements, it may cause engine wear and trigger the malfunction light. Poor mixture combustion: Poor mixture combustion can lead to engine carbon buildup or knocking. When detected by the oxygen sensor and reported to the ECU, the malfunction light will illuminate as a warning. Spark plug failure, ignition coil failure, fuel pump failure, and fuel line blockage can all cause poor mixture combustion in the engine. Turbocharging issues: The intake turbocharging pipeline and turbocharger can also cause the engine malfunction light to illuminate. The most common issue is turbocharger damage, accompanied by symptoms such as oil leaks, high oil consumption, reduced power, metallic noises, and blue or black smoke from the exhaust pipe. Intake issues: If the car's intake system has problems, it may cause engine pipeline blockage, and in severe cases, trigger the engine malfunction light. A dirty air filter that is not cleaned regularly can lead to intake problems. Exhaust issues: Exhaust system malfunctions can also cause the engine malfunction light to illuminate. The rear oxygen sensor, catalytic converter, exhaust camshaft, and bearing failures are all causes of exhaust problems, with the catalytic converter being the most common. Using leaded gasoline, lead or silicon-based lubricant additives, physical damage to the catalytic converter, or engine fuel system failures can easily cause catalytic converter issues. Anti-theft system malfunction: If the car's electronic anti-theft system malfunctions or 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 malfunction light. If the engine malfunction light is on, follow these steps: First, check if the engine is running normally and if there are any issues such as shaking or smoke. If so, 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 depressing the clutch. The car will perform a self-check after powering on. Wait 5-10 seconds and observe if the malfunction light on the dashboard turns off. If the malfunction light remains on, visit a service center as soon as possible. The service center can use a portable diagnostic tool to read the fault codes, identify the issue, and perform targeted repairs.
