Why is the car engine warning light on?

[DiPresley]

There are mainly 7 reasons for the engine warning light to illuminate: Sensor malfunction: The sensors mentioned here include coolant temperature, crankshaft position, air flow, intake air temperature, oxygen sensors, etc. When these sensors are damaged, have poor contact, or signal interruption occurs, the car's ECU cannot accurately obtain engine data, which will then trigger the engine warning light. Fuel quality issues: If fuel and engine oil are not added as required by the manufacturer, it may cause engine wear, leading to the warning light turning on. Poor combustion of air-fuel mixture: Poor combustion of the air-fuel mixture can cause engine carbon buildup or knocking. When detected by the oxygen sensor and reported to the ECU, the warning light will illuminate as a warning. Spark plug failure, ignition coil failure, fuel pump failure, and fuel line blockage can all lead to poor combustion of the engine's air-fuel mixture. Turbocharging issues: The intake turbocharging pipeline and turbocharger can also cause the engine warning light to illuminate. The most common issue is turbocharger damage, accompanied by symptoms such as oil leaks, high oil consumption, reduced power, metallic noises, and blue or black smoke from the exhaust pipe. Intake issues: If there is a problem with the car's intake, it may lead to engine pipeline blockage, and in severe cases, cause the engine warning light to illuminate. A dirty air filter that is not cleaned regularly can lead to intake problems. Exhaust issues: Exhaust faults can also cause the engine warning light to illuminate. The rear oxygen sensor, three-way catalytic converter, exhaust camshaft, and bearing faults are all causes of exhaust problems, with the three-way catalytic converter being the most common. Using leaded gasoline, lead or silicon-containing lubricant additives, physical damage to the three-way catalytic converter, and faults in the engine fuel supply system can easily cause three-way catalytic converter failure. Anti-theft system malfunction: If the car's electronic anti-theft system malfunctions, or if the anti-theft controller does not match the engine electronic controller, the anti-theft system can also cause the engine to malfunction, along with the engine warning light illuminating. If the engine warning light is on, you can follow these steps to address the issue: First, check if the engine is running normally and whether there are issues such as shaking or black smoke. If so, try not to start the engine again. Especially note that if the red light is on, do not start the engine under any circumstances. If the engine can be started, turn it off for 5-10 minutes, then without pressing the brake, press the start button once, or without pressing the clutch, turn the car key halfway to the 'on' position. The car will perform a self-check after powering on. Wait for 5-10 seconds and observe whether the warning light on the dashboard turns off. If the warning light does not turn off, please visit a service station as soon as possible to identify the cause. The service station can use a portable diagnostic tool to read the fault codes, obtain fault information, and perform targeted repairs.