OVERVIEW

This chapter describes electronic instrumentation and the relatively new field of telematics. By the term instrumentation, we mean the equipment and devices that measure engine and other vehicle variables and parameters and display their status to the driver. By the term telematics, we refer to communication of all forms within the vehicle as well as communication to and from the vehicle. Communication within the vehicle takes the form of digital data links between various electronic subsystems. Communication to and from the vehicle spans all communication from voice and digital data via cell or satellite phone systems to digital data sent from land or satellite. Internet connections to an on-board PC (or the like) are included in those categories listed above. This chapter begins with a discussion of electronic instrumentation and concludes with telematics.

From about the late 1920s until the late 1950s, the standard automotive instrumentation included the speedometer, oil pressure gauge, coolant temperature gauge, battery charging rate gauge, and fuel quantity gauge. Strictly speaking, only the latter two are electrical instruments. In fact, this electrical instrumentation was generally regarded as a minor part of the automotive electrical system. By the late 1950s, however, the gauges for oil pressure, coolant temperature, and battery charging rate were replaced by warning lights that were turned on only if specified limits were exceeded. This was done primarily to reduce vehicle cost and because of the presumption that many people did not necessarily regularly monitor these instruments.

Automotive instrumentation was...