There are mainly 7 reasons for the engine malfunction light to illuminate: Sensor failure: The sensors mentioned here include coolant temperature, crankshaft position, air flow, intake temperature, oxygen sensors, etc. When these sensors are damaged, have poor contact, or signal interruption, the vehicle'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 combustion of air-fuel mixture: Poor combustion can lead to engine carbon deposits 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 combustion of the air-fuel mixture. Turbocharging issues: The intake boost piping 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. Intake issues: If the vehicle's intake system has problems, it may lead to engine piping blockage, and in severe cases, the engine malfunction light will illuminate. A dirty air filter that is not cleaned regularly can cause intake problems. Exhaust issues: Exhaust system failures can also trigger the engine malfunction light. The rear oxygen sensor, catalytic converter, exhaust camshaft, and bearing failures are common causes of exhaust problems, 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 fuel system failures can easily cause catalytic converter problems. Anti-theft system failure: If the vehicle'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 start, turn it off and wait for 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 vehicle will enter self-check mode after powering on. Wait for 5-10 seconds and observe if the malfunction light 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.
