My car smog test said my car failed the MIL/check engine light due to warning lamp failure means what?

Basically, it means the check engine warning light didn't light up when it should. Perhaps a burned out bulb?

Every vehicle has a "system check" that happens every time you turn the key on. Most people don't know it is happening right before thier eyes. So if you go out and get into your car in the morning and you turn the key to "on" but then don't go the rest of the way to the "start" position there are several warning lights on. The check engine light is one of them. All the system is doing is running power through the light to show it is functional.

It doesn't mean there is something wrong, it is just showing that an error "can" be displayed if an error existed by the light being on. Try it next time. Turn the key on but dont start the engine. If your check engine light is off, then that is what they stated in the report.