the accident sensor 1 in fig2 curve a the response signal generated by the sensor given a correct method of operation on the line 2 is designated by the reference numeral 5 the start phase corresponds in fig2 to the time range shown to the left of the vertical dashed line in the exemplary embodiment illustrated the accident sensor 1 is a capacitive acceleration sensor embodied as a capacitor with two fixed capacitor plates and a movable center plate disposed between the two fixed capacitor plates the voltage pulse 7 that is fed through the line 3 during the self test deflects the movable center plate serving as seismic mass of the capacitor by electrostatic attraction thus the center plate moves in a way similar to that caused when the motor vehicle severely decelerates due to an imminent accident as a result the internal capacitance values change clearly the sensor evaluates these changes in capacitance internally for example after amplification of the very weak internal signals caused by the change in capacitance and then generates on the line 2 the corresponding analog or digital sensor output signal with the profile shown in fig2 line a pulse 5 depending on the configuration the accident sensor 1 has different internal functions the accident sensor 1 is configured according to the invention such that it can internally check one or more of these internal functions automatically at regular or irregular intervals the accident sensor 1 contains for example an internal memory in particular an eprom in which control data that controls the sensor operation and that can be output while the sensor is operating is stored the control data can for example represent the amplification factor provided for the amplification of the internal capacitive.