Control systems

Most engines require one or more systems to start and shutdown the engine and to control parameters such as the power, speed, torque, pollution, combustion temperature, efficiency and to stabilise the engine from modes of operation that may induce self-damage such as pre-ignition. Such systems may be referred to as engine control units.

Many control systems today are digital, and are frequently termed FADEC (Full Authority Digital Electronic Control) systems.

Diagnostic systems

On Board Diagnostics

Engine On Board Diagnostics (also known as OBD) is a computerized system that allows for electronic diagnosis of a vehicles' powerplant. The first generation, known as OBD1, was introduced 10 years after the U.S. Congress passed the Clean Air Act in 1970 as a way to monitor a vehicles' fuel injection system. OBD2, the second generation of computerized on-board diagnostics, was codified and recommended by the California Air Resource Board in 1994 and became mandatory equipment aboard all vehicles sold in the United States as of 1996.