Computers and Control Systems: Description and Operation

Digital Electronic Fuel Injection (DEFI) provides a means of fuel distribution for controlling exhaust emissions by precisely controlling the air/fuel mixture under all operating conditions. This is accomplished through the use of an Electronic Control Module (ECM). The ECM receives signals from various sensors and transmits signals the injectors to provide the precise amount of fuel required.
A Body Computer Module (BCM) used in conjunction with the ECM provides for additional control capability. The BCM monitors various body operating parameters and shares this information with the ECM through an electronic communications process.
The ECM and BCM are both capable of diagnosing faults with the various inputs and systems they control. When the ECM detects a malfunction, a Service Now or Service Soon warning lamp on the instrument panel is illuminated.