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 system problems, and issues with the anti-theft system. In addition, when starting the car, 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 visit a repair station to seek professional help and eliminate potential safety hazards. Below is a detailed explanation of 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 connections, or experience signal interruptions, the car's ECU cannot accurately obtain engine data, which triggers the engine warning light. Solution: If such issues occur, promptly visit a repair center for professional inspection and eliminate safety hazards. Maintenance Issues: Poor engine maintenance is the most common cause of the engine warning light. Vehicles have specific maintenance cycles. If maintenance is not performed on schedule, combined with poor driving habits, the engine's operational burden increases, 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, and perform comprehensive maintenance to 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 generally recommend which fuel octane rating and oil type to use. If the owner fails to follow these recommendations, long-term use can cause engine wear, triggering the warning light. Solution: Use the appropriate fuel octane rating and engine oil as specified for your vehicle. Poor Combustion of Air-Fuel Mixture: Faulty spark plugs, fuel pump issues, or clogged fuel lines can lead to poor combustion of the air-fuel mixture. This results in engine carbon buildup or knocking, which the oxygen sensor detects and reports to the ECU, triggering the warning light. Intake Issues: During combustion, the engine requires air intake, and the air filter plays a crucial role. If the air filter is dirty or not cleaned regularly, it can affect the engine's air intake, potentially leading to blockages and, in severe cases, illuminating the engine warning light. Solution: Regularly clean or replace the air filter to ensure the intake system functions properly. Turbocharging Issues: Problems with the intake boost piping or turbocharger can also trigger the engine warning light. 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. Solution: Visit a 4S shop to inspect and replace the turbocharger. Typically, repairs are not cost-effective, so replacing the component is recommended. Exhaust Issues: The rear oxygen sensor, catalytic converter, exhaust camshaft, and bearings can cause the warning light. The most common issue is a faulty catalytic converter, which can result from physical damage 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 does not match the engine ECU, the engine may not operate correctly, and the warning light will illuminate. Solution: Visit a professional repair shop for a system check, as this issue cannot be resolved individually. Engine Misfire: This occurs when one or more cylinders fail to work properly, leading to symptoms like reduced power, difficulty starting, or unstable idling. Solution: First, identify which cylinder's components are faulty and replace them. If internal mechanical damage is present, a major repair at a professional shop is necessary.
