Abstract: An improved computerized automotive service equipment system has a number of novel features. The system causes the initiation of a servicing routine upon the detection of particular stimuli from the sensors. The novel system also places instructional output on the output device simultaneously with an output representative of a vehicle diagnostic state. Object oriented programming techniques are utilized to allow an automotive servicing application to be easily and conveniently updated. The automotive service equipment system is constructed so that replacement of the sensor hardware only requires the replacement of a single software object or collection of objects instead of the rewriting of the entire application. In the novel system, the operator/technician can program the sequence in which the automotive service routine will proceed. The system has other novel features as well.