Two problems related to air bag not deploy have been reported for the 2006 Audi A4. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2006 Audi A4 based on all problems reported for the 2006 A4.
At an intersection, a Ford f250 pickup, pulling a trailer, turned left into my 2006 Audi A4 avant. My vehicle was traveling straight through intersection traveling at about 20 to 25 mph. . I was traveling alone, with my seat belt on. My vehicle was crushed up to the firewall and was totaled (photos are available). The air bags on my vehicle did not deploy. The belt tensioner did deploy.
In early September 2010 the air bag warning light came on in my 2006 Audi A4 cabrio and would not turn off. I took the car to be serviced and was told the air bag needed to be replaced. The car has never been in an accident. It is now out of warranty. This part has never been used. If I'd been in an accident the air bag would not have deployed. Although a TSB has not been issued for this problem, I have read similar complaints of this happening to the same car after the same # of years. Suggest that the NHTSA take a look into this issue. Had I been in an accident and needed the airbag to work, it would not have. Since the car has never been in an accident, this indicates the part was faulty all along. A recall should be issued and Audi USA should replace this part free of charge for all vehicle owners to avoid the inevitable lawsuit if the part fails when someone does have an accident.