The service engine soon light, commonly referred to as the check engine light, on a 2000 Chevy Silverado, or any vehicle, can have a number of meanings depending on the issue. If the light is steady, it typically indicates a minor problem, such as a loose gas cap or a failing oxygen sensor. However, if the light flashes, it indicates a severe problem that could potentially damage the catalytic converter.
If the check engine light is on, the engine control unit stores a fault code related to the malfunction. Mechanics can use a scanner tool to see what error or malfunction the light is referring to. The light does not usually indicate any serious issue with the vehicle and should be viewed as a warning. A car can continue running without issue for a long time even if the check engine light is on; although, this is not to say the light cannot occasionally indicate serious trouble.
Often, a check engine light may turn off immediately after repairs but come back on shortly thereafter. This is due to the on-board diagnostics (OBD) system performing constant maintenance tests. Certain tests require specific conditions to be met before they complete, such as the vehicle being off for a certain time or traveling for a certain distance; this can result in the check engine light staying on until the conditions are met and the tests are completed.