Sensor malfunctions, engine misfire, vehicle maintenance issues, fuel quality problems, poor mixture combustion, engine intake issues, turbocharging problems, exhaust system faults, and anti-theft system failures are the main causes of the engine warning light illuminating. Additionally, during vehicle startup, the system performs a self-check on the engine. Normally, the warning light should turn off after the self-check. If it remains lit for an extended period, promptly visit a repair station for professional assistance to diagnose and eliminate potential hazards. Below is a detailed explanation of each fault: Sensor Issues: Sensors such as coolant temperature, crankshaft position, air flow, intake temperature, and oxygen sensors may become damaged, have poor connections, or lose signal transmission. This prevents the ECU from accurately obtaining engine data, triggering the warning light. Solution: Seek immediate professional inspection at a repair center to address safety risks. Maintenance Issues: Poor engine maintenance is the most common cause of the warning light. Vehicles have specific maintenance schedules. Neglecting maintenance and poor driving habits increase engine strain, eventually triggering the warning light. Solution: Follow the maintenance schedule in the vehicle’s manual for timely, comprehensive servicing to rule out non-maintenance-related issues. Fuel Quality Issues: This refers to both fuel and engine oil. Vehicles require specific fuel grades and oil types (semi-synthetic or full synthetic). Using incorrect specifications long-term can cause engine wear and trigger the warning light. Solution: Use the recommended fuel grade and engine oil type for your vehicle. Poor Mixture Combustion: Faulty spark plugs, fuel pump issues, or clogged fuel lines can lead to poor combustion, causing carbon buildup or engine knocking. The oxygen sensor detects these issues, prompting the ECU to illuminate the warning light. Intake Issues: Engine combustion requires proper airflow. A dirty or clogged air filter disrupts intake, potentially causing blockages and triggering the warning light. Solution: Regularly clean or replace the air filter to ensure proper intake system operation. Turbocharging Issues: Problems with the intake turbo piping or turbocharger (e.g., leaks, excessive oil consumption, power loss, unusual noises, or smoke) can trigger the warning light. Solution: Visit a 4S shop to inspect and replace the turbocharger if necessary, as repairs are often impractical. Exhaust Issues: Faults in the rear oxygen sensor, catalytic converter, exhaust camshaft, or bearings—especially catalytic converter damage due to impact or fuel system issues—can trigger the warning light. Solution: Maintain and clean the catalytic converter using lead- or silicon-based lubricants. Anti-Theft System: If the electronic anti-theft system malfunctions or conflicts with the engine ECU, the engine may fail to operate normally, and the warning light may illuminate. Solution: Professional diagnosis and repair are required; individual fixes are not feasible. Engine Misfire: One or more cylinders failing to operate properly can cause power loss, hard starts, or unstable idling. Solution: Identify and replace faulty cylinder components. For internal mechanical damage, seek professional engine overhaul.
