What is a common consequence of having a check engine light illuminated during a Smog Check?

Having the check engine light illuminated during a Smog Check is significant because it indicates that the vehicle's onboard diagnostics system has detected a fault that may affect emissions. When the light is on, the vehicle is typically unable to meet the emissions standards required for passing the Smog Check.

As a result, it automatically fails the inspection. This is in line with California regulations, which aim to ensure that vehicles on the road are not contributing to excessive pollution. The presence of the illuminated check engine light suggests a problem that may require addressing, such as repairs to the emissions system or other related components.

In contrast, options suggesting that the vehicle would pass the inspection, have the warning ignored, or only require a repeat inspection later do not align with the regulations in place designed to promote environmentally friendly practices and emissions control. Thus, a check engine light does indeed lead to an automatic failure of the inspection, reflecting the importance of addressing any diagnostic issues presented before attempting a Smog Check.