The use of computer‐based systems to monitor and display vehicle location is currently an area of strong interest, and a number of organizations have developed such systems. Real‐time vehicle systems monitoring, which can fit hand‐inglove with location monitoring, is less well developed. Our requirement for vehicle data acquisition systems (DAS) was to monitor and store data on driving cycle, temperatures, pressures, engine stoichiometry, etc. In the course of working with fleets, it became clear that if vehicle systems data could be transmitted to a base station in real time, could be interpreted by base station software to provide a diagnostic capability, and could be combined with a map location display capability, then it would be of interest to a large number of fleets. The system, which has recently been developed, consists of enboard vehicle microprocessor monitoring, data reduction and transmission components, a VHF or satellite communications link, a base station signal modem, and an AT‐type microcomputer for data analysis and display. This paper traces the evolution of the microcomputer‐based systems monitoring of vehicles and provides some insight into the capabilities of suc