What are the reasons for the Nissan engine warning light to come on?

[LaCorbin]

The engine warning light may come on due to the following 7 main reasons: Sensor malfunction: This includes sensors such as coolant temperature, crankshaft position, air flow, intake temperature, and oxygen sensors. When these sensors are damaged, have poor connections, or experience signal interruptions, the vehicle's ECU cannot accurately obtain engine data, triggering the engine warning light. Fuel and oil quality issues: Failure to use the fuel and oil as recommended by the manufacturer may cause engine wear, leading to the warning light illuminating. Poor fuel mixture combustion: 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 come on as an alert. Issues such as faulty spark plugs, ignition coils, fuel pumps, or clogged fuel lines can cause poor fuel mixture combustion. Turbocharger problems: Issues with the intake boost pipes or turbocharger can also trigger the engine warning light. The most common issue is a damaged turbocharger, accompanied by symptoms like oil leaks, excessive oil consumption, reduced power, metallic noises, or blue/black smoke from the exhaust. Intake problems: If the vehicle's intake system is compromised, it may lead to clogged engine pipes, and in severe cases, the engine warning light will come on. A dirty or uncleaned air filter can cause intake problems. Exhaust problems: Exhaust system faults can also trigger the engine warning light. Common causes include faulty rear oxygen sensors, catalytic converters, exhaust camshafts, or bearings, 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 cause catalytic converter failure. Anti-theft system malfunction: If the vehicle's electronic anti-theft system fails or if the anti-theft controller is incompatible with the engine ECU, the anti-theft system may prevent the engine from operating normally, accompanied by the engine warning light. If the engine warning light comes on, follow these steps: First, check if the engine is running normally, such as whether there is shaking, black smoke, etc. If so, avoid restarting the engine. Note: Do not restart the engine if the red warning light is on. If the engine can be started, turn it off and wait 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 enter self-diagnosis mode, and after 5-10 seconds, observe whether 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 fault codes, identify the issue, and perform targeted repairs.