The main reasons for the engine warning light to illuminate include sensor issues, engine misfire, vehicle maintenance problems, fuel quality issues, poor combustion of the air-fuel mixture, engine intake problems, turbocharging issues, exhaust problems, and anti-theft system malfunctions. Additionally, when starting the car, the vehicle performs a self-check on the engine system. Normally, the engine warning light should turn off after the self-check. If it remains on for an extended period, you should promptly visit a repair station to seek professional assistance for inspection and to eliminate potential safety hazards. Below are detailed explanations for each type of fault: Sensor Issues: Sensors include coolant temperature, crankshaft position, air flow, intake temperature, oxygen sensors, etc. When these sensors are damaged, have poor contact, or experience signal interruptions, the car's ECU cannot accurately obtain engine data, which will trigger the engine warning light. Solution: If such issues occur, promptly visit a repair center for professional inspection to eliminate safety hazards. Maintenance Issues: Poor engine maintenance is the most common cause of the engine warning light illuminating. Vehicles have specific maintenance cycles. If maintenance is not performed on time, coupled with poor driving habits, the engine's operational burden will increase, eventually causing the engine warning light to illuminate as a reminder of a fault. Solution: Follow the maintenance schedule in your vehicle's manual, either by time or mileage, to ensure comprehensive maintenance and eliminate non-maintenance-related issues. Fuel Quality Issues: This includes both fuel and engine oil. The fuel used in cars usually has a specific octane rating, and engine oil can be semi-synthetic or fully synthetic. Manufacturers typically recommend which fuel octane and oil type to use. If the owner fails to follow these recommendations, long-term use can cause engine wear, leading to the warning light illuminating. Solution: Use the recommended fuel octane and appropriate engine oil for your vehicle. Poor Combustion of Air-Fuel Mixture: Faulty spark plugs, fuel pump issues, or clogged fuel lines can cause poor combustion of the air-fuel mixture. This leads to engine carbon buildup or knocking, which the oxygen sensor detects and reports to the ECU, triggering the warning light. Intake Issues: Engine combustion requires air intake, where the air filter plays a crucial role. If the air filter is dirty or not cleaned regularly, it can affect the intake, potentially leading to blockages and, in severe cases, the engine warning light illuminating. Solution: Regularly clean or replace the air filter to ensure the intake system functions properly. Turbocharging Issues: Problems with the intake boost pipes or turbocharger can also trigger the engine warning light. The most common issue is a damaged turbocharger, accompanied by symptoms like oil leaks, excessive oil consumption, reduced power, metallic noises, or blue/black smoke from the exhaust. Solution: Visit a 4S shop to inspect and replace the turbocharger. Often, repairs are not cost-effective, and replacing the component is a better option. Exhaust Issues: Rear oxygen sensors, catalytic converters, exhaust camshafts, and bearings can cause the warning light to illuminate. The most common issue is a faulty catalytic converter, which can be damaged by impacts or fuel system problems. Solution: Use lead- or silicon-based lubricants to maintain and clean the catalytic converter. Anti-Theft System: If the car's anti-theft system malfunctions or the anti-theft controller is incompatible with the engine ECU, the engine may not operate properly, and the warning light will illuminate. Solution: Visit a professional repair shop for a thorough inspection, as this issue cannot be fixed by individuals. Engine Misfire: This occurs when one or more cylinders fail to operate or perform poorly, leading to symptoms like reduced power, difficulty starting, or unstable idling. Solution: First, identify which cylinder's components are faulty and replace them. If the issue involves internal mechanical damage, a major repair at a professional shop is necessary.
