What does it mean to check the engine emission control system?

[Logan]

Checking the engine emission control system indicates that there is a component issue with the vehicle's engine, and the engine warning light illuminates to alert the owner to inspect the engine components. The engine emission system fault light, commonly referred to as the engine fault light, will illuminate on the dashboard when the ECU detects and reads a fault code. The engine can refer to both the power generation device and the entire machine including the power unit (such as gasoline engines, aircraft engines). Its types include internal combustion engines (e.g., gasoline engines), external combustion engines (e.g., Stirling engines, steam engines), gas turbines (used in racing cars), electric motors, and more.