Computer Command Control
Computer Command Control (CCC) system is an electronically-controlled exhaust emission system that monitors up to 15 different engine/vehicle functions and can control as many as 9 different operations including Evaporative Emission Control.
Vehicles equipped with CCC system have an Electronic Control Module (ECM) that controls vacuum to the canister purge valve by means of a solenoid valve. When system is in the open loop, solenoid is energized and blocks vacuum to purge valve. When system is in closed loop, above a specified RPM, solenoid is de-energized. Vacuum can then be applied to purge valve, releasing accumulated vapors into intake manifold.