What does it mean when the engine warning light is on in a Mercedes-Benz GLC260L?

[EdenMarie]

The main reasons for the engine warning light to illuminate include sensor issues, car maintenance problems, fuel quality issues, poor combustion of the air-fuel mixture, engine intake problems, turbocharging issues, exhaust system 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 will turn off after the self-check is completed. If it remains on for an extended period, it is advisable to promptly visit a repair station for professional assistance to diagnose and eliminate potential safety hazards. Below is a detailed explanation of each type of fault: Sensor Issues: Sensors include those for coolant temperature, crankshaft position, air flow, intake temperature, and oxygen sensors. When these sensors are damaged, have poor contact, or experience signal interruptions, the car's ECU cannot accurately obtain engine data, leading to the illumination of the engine warning light. In such cases, it is essential to seek professional inspection at a repair center to promptly address safety risks. Maintenance Issues: Poor engine maintenance is the most common cause of the engine warning light illuminating. Vehicles have specific maintenance schedules. Failure to adhere to these schedules, combined with poor driving habits, can increase the engine's operational burden, eventually causing the engine warning light to come on as a reminder of a fault. Fuel Quality Issues: This refers to both fuel and engine oil. The fuel used in cars typically has a specific octane rating, and engine oil can be semi-synthetic or fully synthetic. Manufacturers usually recommend the type of fuel and engine oil to use. If the owner fails to follow these recommendations, long-term use can lead to engine wear, triggering the warning light. It is crucial to use the recommended fuel octane rating and the appropriate type of engine oil. Poor Combustion of the Air-Fuel Mixture: Faults in the engine's spark plugs, ignition coils, fuel pump, or clogged fuel lines can cause poor combustion of the air-fuel mixture. This can lead to engine carbon buildup or knocking, which the oxygen sensor will detect and report to the ECU, resulting in the warning light illuminating as a warning. Intake Issues: The engine requires air for combustion, and the air filter plays a critical role in this process. If the air filter is dirty or not cleaned regularly, it can affect the engine's air intake, potentially leading to blockages over time. Severe cases can cause the engine warning light to illuminate. Turbocharging Issues: Problems with the intake turbocharging system or the turbocharger itself can also trigger the engine warning light. The most common issue is a damaged turbocharger, which may also cause symptoms such as oil leaks, excessive oil consumption, reduced power, metallic noises, or blue/black smoke from the exhaust. Exhaust Issues: Faults in the rear oxygen sensor, catalytic converter, exhaust camshaft, or bearings can lead to the engine warning light illuminating. The most common issue is a faulty catalytic converter, which can be caused by using leaded gasoline, lead or silicon-based oil additives, physical damage to the catalytic converter, or issues with the engine's fuel supply system. Anti-Theft System: If the car's electronic anti-theft system malfunctions or if there is a mismatch between the anti-theft controller and the engine's electronic controller, the anti-theft system can prevent the engine from operating normally, accompanied by the illumination of the engine warning light. Solutions for an Illuminated Engine Warning Light: If the engine warning light is on and the car cannot start, this may be due to a faulty fuel pump or ignition components. In such cases, it is recommended to call for assistance immediately. If the engine warning light is on and the car can still be driven but exhibits severe shaking or loss of power, pull over safely and call for roadside assistance. If the engine warning light is on but the car drives normally, this may indicate a faulty sensor. In such cases, you can continue driving cautiously at low to moderate speeds but should visit a repair shop as soon as possible to address the issue.