Central Processing Unit (CPU)

Digital signals received by CPU are used to perform all mathematical computations and logic functions necessary to deliver proper air/fuel mixture. The CPU also calculates spark timing and idle speed information. The CPU commands operation of emission control, closed loop fuel control and diagnostic system.

Fig 1: Electronic Control Module Terminal Identification - All Models Except Fuel Injected and Federal "T" Cars Without 5-Speed Transmission

Courtesy of GENERAL MOTORS COMPANY