There are primarily 7 reasons why the engine warning light may illuminate: Sensor Malfunction: The sensors referred to here include those for coolant temperature, crankshaft position, air flow, intake air temperature, oxygen, 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 warning light. Fuel or Oil Quality Issues: Failure to add fuel or engine oil as required by the manufacturer may cause engine wear, leading to the illumination of the warning light. Poor Combustion of Air-Fuel Mixture: Poor combustion can result in engine carbon buildup or knocking. Once detected by the oxygen sensor and reported to the ECU, the warning light will illuminate as a warning. Issues such as faulty spark plugs, ignition coils, fuel pumps, or clogged fuel lines can all lead to poor combustion of the air-fuel mixture. Turbocharger Problems: The intake boost pipeline or turbocharger can also cause the engine warning light to illuminate. 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 there are issues with the vehicle's intake, it may lead to engine pipeline blockages, and in severe cases, trigger the engine warning light. A dirty air filter that hasn't been cleaned regularly can cause intake problems. Exhaust Issues: Exhaust faults can also cause the engine warning light to illuminate. Common causes include faults in the rear oxygen sensor, catalytic converter, exhaust camshaft, and bearings, with the catalytic converter being the most frequent issue. The use of leaded gasoline, lead or silicon-based lubricant additives, physical damage to the catalytic converter, or fuel system malfunctions can easily lead to catalytic converter failure. Anti-Theft System Fault: 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, also causing the engine warning light to illuminate. If the engine warning light illuminates, follow these steps: First, check if the engine is operating normally, looking for signs like shaking or black smoke. If such symptoms are present, avoid restarting the engine. Note: Do not restart the engine if the light is red. 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 vehicle will perform a self-check upon powering up. Wait for 5-10 seconds to see if the warning light turns off. If the warning 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.
