The engine warning light may illuminate due to the following 7 main reasons: Sensor malfunction: Sensors such as coolant temperature, crankshaft position, air flow, intake temperature, and oxygen sensors may be damaged, have poor contact, or experience signal interruption. When the car's ECU cannot accurately obtain engine data, the engine warning light will illuminate. Fuel quality issues: If fuel or engine oil is not added according to the manufacturer's requirements, it may cause engine wear and trigger the warning light. Poor combustion of the 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 warning light will illuminate as a warning. Issues such as spark plug failure, ignition coil failure, fuel pump failure, or fuel line blockage can cause poor combustion of the air-fuel mixture. Turbocharger issues: Problems with the intake turbo pipeline or turbocharger can also cause the engine warning light to illuminate. The most common issue is turbocharger damage, accompanied by symptoms such as oil leakage, excessive oil consumption, reduced power, metallic noises, or blue/black smoke from the exhaust. Intake issues: If the car's intake system has problems, it may lead to engine pipeline blockage, and in severe cases, the engine warning 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 warning light. Common causes include rear oxygen sensor failure, catalytic converter issues, exhaust camshaft and bearing failure, with the catalytic converter being the most frequent culprit. Using leaded gasoline, lead or silicon-based lubricant additives, physical damage to the catalytic converter, or fuel system malfunctions can easily cause catalytic converter issues. Anti-theft system malfunction: If the car's electronic anti-theft system fails or the anti-theft controller does not match the engine electronic controller, the anti-theft system can prevent the engine from operating normally, and the engine warning light will illuminate. If the engine warning light is on, follow these steps: First, check if the engine is running normally. Look for symptoms 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 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 car will enter self-diagnosis mode after powering on. Wait for 5-10 seconds and observe if the warning light turns off. If the warning light remains on, visit a service center as soon as possible. The service center can use a portable diagnostic tool to read the fault code, identify the issue, and perform targeted repairs.
