If the airbag unit triggers a fault, the light will coem on and on my Sei at least you can't do anything to make it go off, even if you correct the fault.
The only way to reset it is to take it to the dealer, who link it up to their diagnostic equipment and reset the error code.
If they are not a dealer it is unlikly they have the correct equipment, it was dealer only for mine, tried lots of places.
When this light is on I was told by FIAT the airbag won't deploy in an accident, so be carefull about how its fixexd. I kow some people (not garaegs) that have just taken their bulbs out! Definatly don't want that to be the fix the shop you got it from takes, not saying they will though!
For me it was £35 standard signostic charge from FIAT.
Kristian