airbag light question (no it's not about resetting)

[speedking83]

ok, my airbag light started to blink all of a sudden.
i haven't diagnosed the code yet, i'll bring it to my garage whenever im free.
but i just want to know what could possibly be the problem.
my airbag never deployed, never had an accident, never removed the steering wheel, never touched any airbag related components.
it just started to blink really out of the blue.
anyone have same experience?
it's 97 240sx btw. completely stock.
about 85,000 clicks.

and if anyone sorta knows what the problem could be, also do tell me how much around i should expect to repair.
thanks alot guys.