What Causes the Engine Warning Light to Illuminate in a Nissan Sylphy?

[Simon]

There are primarily 7 reasons for the engine warning light to illuminate: Sensor malfunction: The sensors mentioned here include coolant temperature, crankshaft position, air flow, intake 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 warning light. Fuel or oil quality issues: If fuel or engine oil is not added as per the manufacturer's requirements, it may cause engine wear, leading to the illumination of the warning light. Poor combustion of the air-fuel mixture: Poor combustion can result in engine carbon buildup or knocking. When detected by the oxygen sensor and reported to the ECU, the warning light will illuminate as a warning. Issues such as faulty spark plugs, ignition coils, fuel pump, or clogged fuel lines can cause poor combustion of the air-fuel mixture. Turbocharging problems: The intake turbocharging pipeline or turbocharger can also cause the engine warning light to illuminate. The most common issue is turbocharger damage, accompanied by symptoms like oil leaks, excessive oil consumption, reduced power, metallic noises, or blue/black smoke from the exhaust. Intake problems: If there are issues with the vehicle's air intake, it may lead to engine pipeline blockages, and in severe cases, the engine warning light will illuminate. A dirty air filter that hasn't been cleaned regularly can cause intake problems. Exhaust problems: Exhaust faults can also trigger the engine warning light. Causes include faulty rear oxygen sensors, catalytic converter, exhaust camshaft, or bearings, with the catalytic converter being the most common issue. Using leaded gasoline, lead or silicon-based lubricant additives, physical damage to the catalytic converter, or fuel system malfunctions 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 is incompatible with the engine electronic controller, the anti-theft system can prevent the engine from operating normally, accompanied by the illumination of the engine warning light. If the engine warning light is on, follow these steps: First, check if the engine is running normally and whether there are issues like shaking or black smoke. If so, avoid restarting the engine. Note: Do not restart the engine if the red warning light is on. If the engine can start, turn it off 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. Wait 5-10 seconds to see if the warning light turns off. If the warning light remains on, visit a service center as soon as possible. The service center can use a portable diagnostic tool to read the fault code, identify the issue, and perform targeted repairs.