The 2003 Chevy Cavalier's Supplemental Restraint System (SRS) module, often called the airbag control module, is typically located
underneath the dashboard, on the passenger side. However, the exact location can vary slightly depending on the specific trim level and options. It's usually secured with bolts and may be covered by a plastic panel.
Because working with airbags and SRS components is dangerous and potentially lethal if done incorrectly, it is strongly recommended that you have a qualified mechanic locate and service the SRS module. Improper handling can cause accidental deployment and serious injury.