There are two colors for the engine malfunction light: yellow and red. When the yellow malfunction light is on, you can continue driving, but when the red malfunction light is on, you must stop driving immediately. When the yellow malfunction light is on, it serves as a warning, indicating that certain system parameters of the vehicle may have exceeded the set range. The vehicle can still be driven at this time, but some functions may be limited. When the red malfunction light is on, it means the issue is severe, and the vehicle must be stopped immediately. Turn off the engine, refrain from further driving, and check for the source of the malfunction. There are seven main reasons why the engine malfunction light may come on: 1. Sensor Failure: Sensors such as coolant temperature, crankshaft position, air flow, intake temperature, and oxygen sensors may become damaged, have poor connections, or lose signal transmission. When the vehicle's ECU cannot accurately obtain engine data, the engine malfunction light will illuminate. 2. Fuel or Oil Quality Issues: If fuel or engine oil is not added as specified by the manufacturer, it may cause engine wear, leading to the malfunction light turning on. 3. Poor Combustion of Air-Fuel Mixture: Poor combustion can cause engine carbon buildup or knocking. When detected by the oxygen sensor and reported to the ECU, the malfunction light will illuminate as a warning. Issues such as faulty spark plugs, ignition coils, fuel pump failures, or clogged fuel lines can lead to poor combustion. 4. Turbocharger Problems: Issues with the intake boost system or turbocharger can also trigger the engine malfunction light. The most common problem is turbocharger damage, often accompanied by symptoms like oil leaks, excessive oil consumption, reduced power, metallic noises, or blue/black smoke from the exhaust. 5. Intake Problems: If the vehicle's intake system is compromised, it may lead to engine pipe blockages, which can, in severe cases, cause the engine malfunction light to come on. A dirty or uncleaned air filter can also lead to intake issues. 6. Exhaust System Issues: Exhaust system faults can also trigger the engine malfunction light. Common causes include faulty rear oxygen sensors, catalytic converter issues, or problems with the exhaust camshaft and bearings. The catalytic converter is particularly susceptible to damage from leaded gasoline, improper oil additives, physical impacts, or fuel system malfunctions. 7. Anti-Theft System Failure: If the vehicle's electronic anti-theft system malfunctions or if the anti-theft controller does not match the engine's electronic controller, the anti-theft system may prevent the engine from operating normally, causing the malfunction light to illuminate. If the engine malfunction light comes on, follow these steps: 1. First, check whether the engine is running normally. If there are issues like shaking or smoke, avoid restarting the engine. Note: If the red light is on, do not restart the engine under any circumstances. 2. 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 vehicle will perform a self-check, and after 5-10 seconds, observe whether the malfunction light turns off. 3. If the light remains on, visit a service center as soon as possible. Technicians can use a portable diagnostic tool to read the fault code, identify the issue, and perform targeted repairs.
