Allroad, A4, A6, A8, S4, S8 & TT
WARNING: This page does not describe the selected car, but rather 120 other vehicles, including the 2002 Volkswagen Passat, 2002 Volkswagen New Beetle, 2002 Volkswagen Jetta, 2002 Volkswagen Golf, and 2002 Volkswagen GTI. However, it is still accessible from the selected car via links, so may be relevant.
Turn ignition switch to ON position. AIR BAG indicator light should come on for about 4 seconds, and then go out. If light remains on, goes out and comes back on, or flashes continuously, air bag control unit has detected a system fault.