The Airbag lights came on today. I have a 1999 Toyota Avalon. What does this mean? Is the car safe to drive? How do I fix?
Your owner’s manual should have specifics, but it most likely means that the airbag system has been disengaged for some reason. The car is perfectly safe to drive as long as you don’t hit anything. 
Have a look as your fuses and see if there’s one for the airbag system. It might be blown. Same goes for the relays.
The car is safe. The Airbag system is off if the light is on. The air bag controller has detected a problem, and turned on the light to let you know. Anytime the light is on, the air bag system is off to prevent an incorrect deployment. This system is different than the engine computer, and is not read by an standard ODB-II scan tool. Take it to the dealer to get the system scanned, and determine what the problem is.
Thanks