A failure monitoring system is provided which may be employed in an automotive passenger restraint system adapted to be responsive to electric power applied from a power source to operate for protecting a vehicle occupant from impact upon occurrence of a vehicle collision. The failure monitoring system provides a failure monitoring signal to a predetermined element in the passenger restraint system before a preselected period of time has expired following actuation of an ignition switch, and monitors an operational condition of the predetermined element to detect occurrence of failure in the passenger restraint system based on the monitored operational condition.