The Passat B51.8T sedan, since the airbag system is an important automotive safety device, all models are not supported by backup mode when the alarm lights are on, and all models will not continue to operate with airbags and seat belt tensioners. This is different from the engine electronic control system. Unlike the ABS system, in automotive braking systems, even if the ABS system is out of operation due to a malfunction, there is a normal braking system that can continue to be used. After replacing the airbag system components according to the correct part number, the airbag alarm lights are still lit for the following reasons: