What does the illumination of the 'check engine' light typically indicate?

The illumination of the 'check engine' light is primarily an alert that something may be amiss within the vehicle's emissions-related systems. When this light comes on, it signifies that the onboard diagnostics system has detected a fault that can affect the vehicle's air-fuel mixture, exhaust emissions, or engine performance. This could involve issues such as a malfunctioning oxygen sensor, a failing catalytic converter, or problems with the fuel system.

The 'check engine' light serves as an important warning to drivers, encouraging them to investigate the issue further. Ignoring this light could lead to more significant problems, including increased emissions, damage to the engine, or reduced fuel efficiency. Therefore, addressing the underlying causes indicated by the 'check engine' light is essential for maintaining vehicle health and compliance with emissions regulations.