Technician Handbook ! 673 Electronic & Computer Controlled Systems Electronic Control Units In the 1970’s, the decreasing cost and increasing power of computerized microprocessors launched the personal computer industry. Because of their speed and flexibility in carrying out complex functions, microprocessors were adapted for hundreds of uses beyond personal computers. The first microprocessors began appearing in automotive engine control systems in the early 1980s. In automotive applications, they became known as electronic control units (ECUs) . Today, some vehicles may have dozens of ECUs controlling a wide variety of vehicle systems, including:
• Engine controls • Transmission • Braking • Steering • Air conditioning • Door locks • Suspension • Cruise control • Tire pressure monitoring • and many other systems. 6 Technical Training