Method for operating a restraint system connected to a bus line during faulty power supply

The present invention concerns a method for operating a restraint system networked via a bus line in conjunction with a defective power supply, in which a central control unit and a plurality of data processing units are connected to the bus line, each of the data processing units being intended to drive one or more restraint devices, and the power for the data processing units being supplied from the central control unit. The restraint system is composed of a central control unit, which is connected via a bus line to a plurality of data processing units each of which is intended to drive one or more restraint devices. To keep the restraint system operational if the power supply in the central control unit becomes defective, a changeover to the vehicle battery voltage as the new supply voltage is effected in the central control unit. The central control unit then signals the changeover to the new supply voltage to all the data processing units. All the data processing units thereupon adjust their circuits to the new supply-voltage level.