Driver-Side Air Bag Module
WARNING: This page is about a different car, the 2002 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
When impact sensor and safing sensor close, signaling an impact, ignitor triggers inflator. During ignition, sodium azide reacts with copper oxide, 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. Driver-side air bag module is not serviceable and must be replaced as a complete assembly.