What Does It Mean When the Engine Malfunction Light Comes On?

[DelHaley]

The engine malfunction light may illuminate due to the following 7 main reasons: 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 experience signal interruption, the vehicle's ECU cannot accurately obtain engine data, which may trigger the engine malfunction light. Fuel quality issues: Failure to add fuel and engine oil as required by the manufacturer may cause engine wear, leading to the illumination of the malfunction light. Poor combustion of the air-fuel mixture: Poor 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 combustion of the engine's air-fuel mixture. Turbocharging issues: The intake turbocharging pipeline and turbocharger can also cause the engine malfunction light to come on. 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 there is a problem with the vehicle's intake, 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 faults can also cause the engine malfunction light to illuminate. The rear oxygen sensor, three-way catalytic converter, exhaust camshaft, and bearing failures are all potential causes of exhaust problems, with the three-way catalytic converter being the most common. Using leaded gasoline, lead or silicon-containing lubricant additives, physical damage to the three-way catalytic converter, or fuel system failures can easily cause three-way catalytic converter issues. Anti-theft system malfunction: If the vehicle's electronic anti-theft system malfunctions, or if 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 engine malfunction light. If the engine malfunction light comes on, follow these steps: First, check if the engine is running normally, and whether there are issues such as shaking or black smoke. If so, avoid restarting the engine. Especially note that if the red light is on, do not restart the engine under any circumstances. If the engine can be started, turn it off and wait 5-10 minutes. Without pressing the brake, press the start button once, or without pressing the clutch, turn the key halfway to the 'on' position. The vehicle will perform a self-check after powering on. Wait 5-10 seconds and observe whether the malfunction light on the dashboard turns off. If the malfunction light does not turn off, visit a service station as soon as possible to identify the cause. The service station can use a portable diagnostic tool to read the fault codes, obtain fault information, and perform targeted repairs.