What Causes the Engine Fault Light to Illuminate in a New Car?

[AlejandroMarie]

There are primarily 7 reasons for the engine fault light to illuminate: Sensor malfunction: The sensors referred to here include coolant temperature, crankshaft position, air flow, intake air temperature, oxygen sensors, etc. When these sensors are damaged, have poor contact, or experience signal interruption, the vehicle's ECU cannot accurately obtain engine data, which triggers the engine fault light. Fuel quality issues: If fuel and engine oil are not added according to the manufacturer's requirements, it may cause engine wear, leading to the illumination of the fault light. Poor mixture combustion: Poor mixture combustion can cause engine carbon buildup or detonation. When detected by the oxygen sensor and reported to the ECU, the fault light will illuminate as a warning. Spark plug failure, ignition coil failure, fuel pump failure, and fuel line blockage can all lead to poor mixture combustion in the engine. Turbocharging issues: The intake boost pipeline and turbocharger can also cause the engine fault light to illuminate. The most common issue is turbocharger damage, accompanied by symptoms such as oil leaks, excessive oil consumption, reduced power, metallic noises, and blue or black smoke from the exhaust pipe. Intake issues: If there is a problem with the vehicle's intake, it may cause engine pipeline blockage, and in severe cases, trigger the engine fault light. A dirty air filter that is not cleaned regularly can lead to intake problems. Exhaust issues: Exhaust faults can also cause the engine fault light to illuminate. The rear oxygen sensor, catalytic converter, exhaust camshaft, and bearing failures are all causes of exhaust problems, with the catalytic converter being the most common. Using leaded gasoline, lead or silicon-based lubricant additives, physical damage to the catalytic converter, or faults in the engine fuel supply system can easily cause catalytic converter failure. Anti-theft system malfunction: If the vehicle's electronic anti-theft system malfunctions, or if the anti-theft controller does not match the engine electronic controller, the anti-theft system can prevent the engine from operating normally and trigger the engine fault light. If the engine fault light illuminates, follow these steps: First, check whether the engine is running normally and if there are issues such as shaking or black smoke. If so, avoid restarting the engine. Note: Do not restart the engine if the red light is on. If the engine can be started, turn it off and wait for 5-10 minutes. Without pressing the brake, press the start button once, or turn the key halfway to the 'on' position without depressing the clutch. The vehicle will perform a self-check after powering on. Observe whether the fault light on the dashboard turns off after 5-10 seconds. If the fault light remains on, visit a service center as soon as possible to identify the cause. The service center can use a portable diagnostic tool to read the fault code, obtain fault information, and perform targeted repairs.