Airbag light dissapears

When I purchased my 98 3.1 144k Lumina the Airbag light was already on, I have no idea how long it was on before i got it, and I turned the engine over one day, the airbag light started flashing as usual, but this time didn't stay on.

Is this a feature? If the airbag light is on long enough without a resolution it turns itself off, or does this indicate the problem has fixed itself?

If the lite came on and went off the SIRS system has checked itself on start up and is ok, for now.