Patent ID: 6652001
Filing Date: 2003-11-25
Classification: B60R

Abstract:
A passive safety device for a vehicle, comprising:a passive safety unit for protecting a passenger in a vehicle; an ignition circuit, connected to an on-board power source, for applying an operating current to said passive safety unit to actuate said passive safety unit; a backup capacitor, connected to the on-board power source and said ignition circuit, for applying the operating current to said passive safety unit when said ignition circuit is disconnected from the power source; a control part, connected to the on-board power source and the backup capacitor, for controlling said ignition circuit; and a nonvolatile memory in which failure diagnosis information is stored, wherein said control part has first means for writing predetermined data in said nonvolatile memory after a predetermined time has elapsed when the on-board power source is turned off; and second means for reading the predetermined data written in said nonvolatile memory, when the on-board power source is turned on, for judging whether the predetermined data is written in said nonvolatile memory or not, and for determining said backup capacitor not to be working normally if the judgement shows that said predetermined data is not written in said nonvolatile memory.