Air Bag Module
WARNING: This page is about a different car, the 1993 Subaru SVX. However, it is still accessible from the selected car via links, so may be relevant.
The air bag module is located in center of the steering wheel and contains an air bag and inflator. When front impact sensor(s) close, signaling a front impact, the ignitor causes ignition of inflator gas generant. This ignition reaction combusts sodium azide/copper oxide gas generant in the inflator, producing nitrogen gas, which inflates air bag.
When air bag deploys, tear seams molded into steering wheel trim cover separate, allowing inflation of air bag assembly. Air bag module is not serviceable and must be replaced as complete assembly.