Front Air Bag Sensor Control problems of the 2000 Chevrolet Blazer

I took my year 2000 Chevrolet Blazer into gleason Chevrolet in forest park illinois to service an inoperable horn. I was told that the front air bag module needed to be replaced in order for the horn to be repaired. (the extended warranty will not cover the cost of repairs. ) I now am concerned that I have two safety issues. 1. ) the horn does not work. 2. ) apparently, the air bag module is defective. Gm will not cover the cost of repairs.