Computers and Control Systems: Description and Operation

Computer Command Control System:

Control Module - Block Diagram:

SYSTEM DESCRIPTION

The Computer Command Control System (C3) has either a Engine Control Module (ECM) or a Powertrain Control Module (PCM). The C3 system, through these modules, can monitor a number of engine and vehicle operating functions which control the following systems:

1. Fuel Delivery
2. Ignition / Electronic Spark Timing (EST)
3. Electronic Spark Control (ESC)
4. Air Management (AIR)
5. Exhaust Gas Recirculation (EGR)
6. Torque Converter Clutch (TCC) with ECM.
6. Automatic Transmission Control with PCM.

The C3 system has a built-in diagnostic system that recognizes and identifies possible operational problems. The C3 system signals the driver through a Malfunction Indicator Lamp (MIL) (Service Engine Soon light) located on the instrument panel. The MIL light will remain "ON" until the problem is identified and repaired. This same light is combined with the built-in diagnostic system in order to assist the technician in locating and correcting problems within the C3 system. It does this by flashing a series of codes which identify the possible problem areas at fault, within the C3 system. The system also allows for near normal driving conditions during system malfunction, through the use of the built-in backup system. The backup system remains in effect until repairs can be made.