System Description

Fig. 1 Computer Command Control (C-3) System Operation Full Function System:

The Computer Command Control (C-3) System uses an Engine Control Module (ECM) to control carburetion and emission systems.

A "full function" C-3 system optimizes engine performance for a wide range of operating conditions by adjusting up to nine engine related systems in response to as many as 15 sensor and switch inputs--See Fig 1.

Systems Controlled
- Fuel Control And Air Management Systems
- Ignition Timing
- Idle Speed Control (ISC)
- Exhaust Gas Recirculation (EGR)
- Early Fuel Evaporation (EFE)
- Evaporative Emission Control (EEC)
- Transmission Torque Converter Clutch (TCC)

NOTE: Systems controlled depend on the application.

On Board Diagnostics & Check Engine Lamp
The system has a built in diagnostic system which monitors selected circuits and notifies the driver of any problems detected by illuminating the "Check Engine" lamp located in the instrument panel--which remains lit until the problem is rectified.

The Check Engine lamp may be used to display--as a series of flashes--the trouble code corresponding to the detected problem.

Limp-In Operation
The system also contains a backup program allowing for near normal operation--in the event of a system malfunction--until repairs can be made.


E-Cell Operation
Controls voltage at ECM terminal 15 providing a different control value for some systems during the break-in period.
- For the first 25,000 miles of vehicle operation the voltage at ECM terminal 15 is nearly zero.
- After the first 25,000 miles of vehicle operation the "E" cell raises the voltage at ECM terminal 15 to near 5 volts.