There is a sensor built into the OBD system that monitors the proper function of the air bag. if you have changed the steering wheel to one that does not have an airbag, or the proper air bag, that light is on because its trying to tell you that something is wrong with your airbag system. the only way that i know to get the light turned off, is to do some wiring to %26quot;trick%26quot; the sensor, or to remove the bulb...but i would not recommend either of these as something is wrong with your vehicle and in a crash, that light being off wont help you any...
ive seen a few people with the same problem, and they just removed the bulb.