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

[DiArianna]

There are mainly 7 reasons for the engine malfunction 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 experience signal interruption, the car's ECU cannot accurately obtain engine data, which will then trigger the engine malfunction light. Fuel and oil quality issues: If fuel and engine oil are not added as required by the manufacturer, it may cause engine wear, leading to the malfunction light illuminating. Poor combustion of the air-fuel mixture: Poor combustion can cause engine carbon buildup or knocking. When detected by the oxygen sensor and reported to the ECU, the malfunction 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 air-fuel mixture. Turbocharging issues: The intake turbocharging pipeline and turbocharger can also cause the engine malfunction 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 car's intake, it may cause engine pipeline blockage, and in severe cases, trigger the engine malfunction light. A dirty air filter that is not cleaned regularly can lead to intake problems. Exhaust issues: Exhaust malfunctions can also cause the engine malfunction light to illuminate. Common causes include rear oxygen sensor failure, catalytic converter failure, exhaust camshaft and bearing failure, with the catalytic converter being the most frequent issue. Using leaded gasoline, lead or silicon-based lubricant additives, physical damage to the catalytic converter, or fuel system malfunctions can easily lead to 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, accompanied by the illumination of the engine malfunction light. If the engine malfunction light illuminates, follow these steps: First, check if the engine is running normally and whether there are issues such as shaking or black smoke. If so, avoid restarting the engine. Especially note that if the red light is on, do not restart 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 turn the key halfway to the 'on' position without pressing the clutch. The car will perform a self-check after powering on. Wait for 5-10 seconds and observe whether the malfunction light on the dashboard turns off. If the malfunction light remains on, visit a service center as soon as possible to diagnose the issue. The service center can use a portable diagnostic tool to read the fault codes, obtain fault information, and perform targeted repairs.

[MacArianna]

In my over ten years of car repair experience, the most common cause for warning lights in new cars is fuel quality issues. Freshly manufactured vehicles are particularly sensitive - using substandard gasoline or failing to use the required 95-octane fuel will immediately trigger oxygen sensor errors. Another frequent issue is loose connectors during transportation, especially in exhaust system sensor wiring harnesses. Don't underestimate a loose fuel cap either - it can trigger warnings too. Last time, a customer's warning light came on during highway driving because they didn't properly close the cap after self-service refueling. The most troublesome cases are false alarms from the engine control module, which require reprogramming. My advice: first tighten the fuel cap and drive for a couple days. If that doesn't work, go straight to the dealership to read the fault codes - repairs are free during the warranty period, so don't attempt DIY fixes.