it probably one of the impact sensors. dont worry your airbag wont go off. just plug it back i to stop the light blinkng duh. if the airbag light is on that means there is something wrong with the airbag crash system. an error as u were. so the default procedure is to deactivate the system. in other words the airbag will no go off if u have a bad enough accident. so dont get in one.
and why did you unplug it in the first place?
and why did you unplug it in the first place?