What Causes the Engine Malfunction Light to Illuminate on the Car Dashboard?

[LaOlive]

There are primarily 7 reasons why the engine malfunction light illuminates: Sensor malfunction: The sensors mentioned here include those for coolant temperature, crankshaft position, air flow, intake temperature, oxygen, etc. When these sensors are damaged, have poor contact, or experience signal interruption, the car's ECU cannot accurately obtain engine data, triggering the engine malfunction light. Fuel or oil quality issues: If fuel or engine oil is not added as required by the manufacturer, it may cause engine wear, leading to the malfunction light turning on. 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. Faulty spark plugs, ignition coils, fuel pumps, or clogged fuel lines can all cause poor combustion of the air-fuel mixture. Turbocharging issues: The intake turbocharging pipeline or turbocharger can also cause the engine malfunction light to illuminate. The most common issue is turbocharger damage, accompanied by symptoms such as oil leaks, excessive oil consumption, reduced power, metallic noises, or blue/black smoke from the exhaust. Intake problems: If the car's intake system has issues, it may lead to engine pipeline blockages, and in severe cases, the engine malfunction light will illuminate. A dirty air filter that is not cleaned regularly can cause intake problems. Exhaust problems: Exhaust system faults can also trigger the engine malfunction light. Common causes include faulty rear oxygen sensors, catalytic converters, exhaust camshafts, or bearings. The catalytic converter is the most frequently affected component. Using leaded gasoline, lead- or silicon-containing lubricant additives, physical damage to the catalytic converter, or fuel system malfunctions can all lead to catalytic converter issues. Anti-theft system malfunction: If the car's electronic anti-theft system fails 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 the engine malfunction light will illuminate. If the engine malfunction light is on, follow these steps: First, check whether the engine is running normally. If there are issues such as shaking or black smoke, avoid restarting the engine. Note: If the light is red, do not restart the engine under any circumstances. If the engine can start, 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 car will perform a self-check after powering on. Wait 5-10 seconds to see if the malfunction light turns off. If the light remains on, visit a service station as soon as possible. Technicians can use a portable diagnostic tool to read the fault code, identify the issue, and perform targeted repairs.