Computers and Control Systems: Description and Operation

SYSTEM DESCRIPTION

The Computer Command Control (C3) system is an electronically controlled emission system that can monitor as many as fifteen different engine/vehicle operating conditions. The Electronic Control Module (ECM), the control center of the C3 system, processes the information and signals the commands to various engine performance related systems.

The C3 system has a built-in diagnostic system that recognizes and identifies possible operational problems, and signals the driver through a "SERVICE ENGINE SOON" ("CHECK ENGINE") Light located on the instrument panel. The "SERVICE ENGINE SOON" ("CHECK ENGINE") light will remain in the "ON" position until the problem is identified and repaired. This same light is used with the built-in diagnostic system in order to assist the technician in locating and correcting problems within the CEC system. It does this by flashing a series of codes which identify the possible problem areas, at fault, within the system.

The system also allows for near normal driving conditions during system malfunction, through the use of a built-in backup system. The backup system remains in effect until repairs can be made.