Publisher Summary This chapter describes electronic instrumentation and telematics. It presents an overview of typical automotive electronic instrumentation. In addition to providing measurements for display, modern automative instrumentation performs limited diagnosis of problems with various subsystems. 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. The chapter presents an overview of typical automotive electronic instrumentation. Low-cost solid-state electronics, including microprocessors, display devices, and sensors, have brought about major changes in the automative instrumentation. The inputs to a instrumentation computer include sensors for measuring various vehicle variables as well as diagnostic inputs from the other critical electronic subsystems. Automobile Internet connectivity opens a limitless range of services for the driver, from on-line navigation help to on-line diagnostic and/or road service for mechanical problems. One of the major issues in telematics is how to present information and services to the driver without distracting him or her from the driving tasks. In certain automobile models, the instrumentation computer can perform the important function of diagnosis of the electronic engine control system.