My airbag light has been on for about 4 months. My car was hit from behind, the airbags did not activate, the other car was only going about 20 to 25 mph and the damage was light. But ever since i got the car back from the auto body shop my airbag light has been on and the dealer wants about $100 to scan it. Is it possible there is a crash code in the computer setting it off even though the airbags never activated. Is there a scanner i can buy to do it myself, one that reads engine & airbag codes.