Why does the engine warning light still come on after adding engine oil?

[VonFernando]

If the warning light still comes on after adding engine oil, it may be due to a faulty oil sensor or poor combustion of the air-fuel mixture. Sensor: When the sensor is damaged, has poor contact, or the signal is interrupted, the car's ECU cannot accurately obtain engine data, causing the engine warning light to illuminate. Poor combustion of air-fuel mixture: Poor combustion of the air-fuel mixture leads to engine carbon deposits or knocking problems, which are detected by the engine's oxygen sensor and transmitted to the ECU, triggering the warning light as an alert. Faulty spark plugs, ignition coils, fuel pumps, or clogged fuel lines can all cause poor combustion of the air-fuel mixture in the engine. Additionally, low viscosity of lubricating oil, poor sealing and lubrication of oil passages, excessive viscosity of cold lubricating oil, or excessive sludge deposits in the lubricating oil can also cause abnormal display of the engine warning light.