Sensor issues, car maintenance problems, fuel quality problems, poor combustion of the air-fuel mixture, engine intake problems, turbocharging issues, exhaust problems, and anti-theft system malfunctions are the main causes of the engine warning light turning on. Additionally, when the car is started, the vehicle performs a self-check on the engine system. Normally, the engine warning light will turn off after the self-check is completed. If it remains on for an extended period, you should promptly seek professional help at a repair station to diagnose and eliminate potential safety hazards. Below is a detailed explanation of each type of fault: Sensor problems: Sensors 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 car's ECU cannot accurately obtain engine data, which will cause the engine warning light to turn on. In such cases, you should promptly visit a repair center for professional diagnosis and elimination of safety hazards. Maintenance issues: Poor engine maintenance is the most common cause of the engine warning light turning on. Vehicles have a certain maintenance cycle. If maintenance is not performed on schedule, coupled with poor driving habits, the burden on the engine will increase, and eventually, the engine warning light will turn on to alert the owner of a fault. Fuel quality issues: This includes both fuel and engine oil. The fuel added to a car usually has a specific grade, and engine oil can be semi-synthetic or fully synthetic. Manufacturers generally recommend which grade of fuel and type of engine oil to use. If the owner does not follow these recommendations, long-term use can cause engine wear, and the warning light will turn on. Always use the recommended fuel grade and engine oil for your vehicle. Poor combustion of the air-fuel mixture: Faulty spark plugs, ignition coils, fuel pumps, or clogged fuel lines can cause poor combustion of the air-fuel mixture in the engine. Poor combustion leads to engine carbon buildup or knocking, which is detected by the engine's oxygen sensor and reported to the ECU, triggering the warning light. Intake problems: The engine requires air for combustion, and the air filter plays a crucial role in this process. If the car's air filter is dirty or not cleaned regularly, it can affect the engine's air intake. Over time, this can lead to blockages and, in severe cases, cause the engine warning light to turn on. Turbocharging issues: Problems with the intake turbocharging pipeline or turbocharger can also cause the engine warning light to turn on. 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. Exhaust problems: Faults in the rear oxygen sensor, catalytic converter, exhaust camshaft, or bearings can trigger the engine warning light. The most common issue is a faulty catalytic converter. Factors such as using leaded gasoline, lead- or silicon-containing lubricant additives, physical damage to the catalytic converter, or fuel system malfunctions can easily cause catalytic converter failure. Anti-theft system: If the car's electronic anti-theft system malfunctions or the anti-theft controller is incompatible with the engine's electronic controller, the anti-theft system can prevent the engine from operating normally, and the engine warning light will turn on. There are two scenarios when the engine warning light turns on: one is a yellow light, indicating a warning that certain system parameters may be out of range. The car can still be driven, but some functions may be limited. The other is a red light, which means the car must be stopped immediately, the engine turned off, and driving prohibited until the fault is checked. Solutions for the engine warning light: If the engine warning light turns on and the car cannot start, this may be due to a faulty fuel pump or ignition components. It is recommended to call for assistance. If the engine warning light turns on and the car can still be driven but exhibits severe shaking or loss of acceleration, pull over and call for roadside assistance. If the engine warning light turns on but there are no noticeable driving issues, it may be due to a faulty sensor. In this case, you can continue driving at low speeds but should visit a repair shop as soon as possible to eliminate safety hazards.
