My airbag light is on in my 02 camry what does that mean on 2002 Toyota Camry

It came on right after we put another transmission in

Asked by for the 2002 Toyota Camry
1 answer 1 comment
Possible damaged wiring to air bag system, left side of vehicle. Check fuses. Can be scan tested!
Is this an expensive repair? What should I say to the mechanic? the light just came on today as I was preparing to take the car for inspection.