The airbag warning light should only stay on when there's a problem with the airbag system in the car. Every time you turn on the car, the computer in the vehicle checks the system. The light comes on for a few seconds and then goes off to show that it's working. If it remains on, then there's a problem with the system, and the airbag may not deploy in an accident.
The airbag light in your car potentially indicates a few different things. If your airbag has been deployed and has not been properly reset, the airbag light will be on. If the airbag hasn't been deployed, the light will come on when the system senses that it cannot activate the airbag; this means that there is some sort of a problem with the airbag system in your vehicle. You'll need to reset the airbag light in this case.
There's no quick and easy way to troubleshoot the problem of an airbag warning light. Much like the Check Engine light, it should not be ignored and needs to be looked at by a professional. In this case the mechanic will run a diagnostic on the airbag ECU, or electronic control unit. This is where all the data is stored.
In the case in which your airbags have not become activated or discharged but you're still seeing an airbag light, there is likely some sort of a computer problem. This could be either that the airbag system has become deactivated and faulty for some reason, or that the computer has simply made an error and that the airbags are correct.
Before you can use the airbag and the airbag warning light can shut off, the airbag ECU has to be cleared. If you're convinced there's no problem in the system, remove the airbag ECU and send it off to a company that does the work, and they will clear it for you. Your car dealer will also be able to perform this, although they will be more likely to install a brand new airbag ECU, after which the airbag warning light should remain off.
Take the Vehicle to a Mechanic
The best thing to do if your airbag light has come on is to take the vehicle to a mechanic right away. A mechanic can help you to deal with the airbag light by examining the system with the help of the car diagnostic internal system. He will then adjust the airbag sensor or determine what else may be the problem with the airbag system.
If the airbag light is on, it means that the airbag will not be able to deploy in the event of an accident. This is a dangerous proposition, and it means that you should avoid driving if at all possible in that vehicle.