What Causes the Engine Malfunction Light to Flash?

[LeEllie]

When the engine malfunction light flashes, it indicates a fault in the engine, and the issue is relatively severe, requiring immediate inspection. The specific reasons may include the following seven possibilities: Sensor malfunction: 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 experience signal interruption, the vehicle's ECU cannot accurately obtain engine data, which triggers the engine malfunction light. Fuel or oil quality issues: If fuel or engine oil is not added according to the manufacturer's requirements, it may cause engine wear, leading to the illumination of the malfunction light. Poor combustion of the air-fuel mixture: Poor combustion can result in 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 all lead to poor combustion. Turbocharger problems: The intake boost pipeline or turbocharger can also trigger the engine malfunction light. The most common issue is turbocharger damage, accompanied by symptoms like oil leaks, excessive oil consumption, reduced power, metallic noises, or blue/black smoke from the exhaust. Intake problems: If the vehicle's intake system malfunctions, it may cause engine pipeline blockages, and in severe cases, trigger the engine malfunction light. A dirty air filter that is not cleaned regularly can lead to intake issues. Exhaust problems: Exhaust system faults can also cause the engine malfunction light to illuminate. Issues such as rear oxygen sensor failure, catalytic converter problems, exhaust camshaft or bearing faults are common causes, with the catalytic converter being the most frequent. The use of leaded gasoline, lead- or silicon-containing lubricant additives, physical damage to the catalytic converter, or fuel system malfunctions can all contribute to catalytic converter failure. Anti-theft system malfunction: If the vehicle's electronic anti-theft system fails or the anti-theft controller does not match the engine ECU, the anti-theft system can prevent the engine from operating normally, while also triggering the engine malfunction light. Generally, the engine malfunction light can appear in four states: steady yellow light, flashing yellow light, steady red light, or flashing red light. The severity of the issue increases from steady to flashing and from yellow to red. In order of severity: flashing red > flashing yellow/red > steady red > steady yellow. If the engine malfunction light illuminates, follow these steps: First, check whether the engine is running normally, including any signs of shaking or black smoke. If such issues exist, avoid restarting the engine. Note: Do not restart the engine if the red light is on. If the engine can be started, turn it off for 5-10 minutes, then press the start button without pressing the brake pedal, or turn the key halfway to the 'ON' position without depressing the clutch. The vehicle will perform a self-check after powering on. Wait for 5-10 seconds and observe whether the malfunction light turns off. If the light remains on, visit a service center as soon as possible. The service center can use a portable diagnostic tool to read fault codes, identify the issue, and perform targeted repairs.