The airbag light went on (a checking light).

You'll need to have it scanned to see what the code is. Most likely a driver seat belt buckle code or a driver seat air bag code.

Can't tell over the internet.

When the air bag light is ON, the air bags will not deploy deploy in an accident, so don't leave it alone, as insurance companies
might not pay damages in an accident if there was a fault with the air bag system.

Thomas