There are primarily 7 reasons for the engine warning light to 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 will trigger the engine warning 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 warning light. Poor combustion of the air-fuel mixture: Poor combustion can lead to engine carbon deposits or knocking. Once detected by the oxygen sensor and reported to the ECU, the warning 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 and turbocharger can also cause the engine warning light to illuminate. The most common issue is a damaged turbocharger, accompanied by symptoms such as oil leaks, excessive oil consumption, reduced power, metallic noises, or blue/black smoke from the exhaust pipe. Intake issues: If the vehicle's intake system encounters problems, it may lead to clogged engine pipelines, 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. Using leaded gasoline, lead or silicon-based lubricant additives, physical damage to the catalytic converter, or faults in the engine fuel supply system can easily lead to catalytic converter failure. 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, while also illuminating the engine warning light. If the engine warning light is on, follow these steps: First, check whether the engine is running normally, such as whether there is shaking, black smoke, etc. If so, try not to start the engine again. Particularly, do not start the engine if the red warning light is on. If the engine can be started, turn it off for 5-10 minutes, then 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 after powering on. Wait for 5-10 seconds to observe whether the warning light on the dashboard turns off. If the warning 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.
