EFI CEC System: Description
The General Motors Computer Control System (GMCCS) is a computerized emission, ignition and fuel control system. The GMCCS controls Electronic Fuel Injection (EFI), engine operation and lowers exhaust emissions while maintaining good fuel economy and driveability.
The Electronic Control Module (ECM) controls the GMCCS. The ECM contains preprogrammed information which has all data necessary for maintaining optimum ignition timing under all operating conditions. Input from the various data sensors allows the ECM to deliver spark at exactly the right moment. The ECM controls many engine related systems to constantly adjust engine operation. See Fig 1 .
The GMCCS is primarily and emission control system, designed to maintain an ideal air/fuel ratio of 14.7:1 under all operating conditions. When an ideal air/fuel ratio is maintained, the catalytic converter can control Carbon Monoxide (CO), Hydrocarbons (HC), and Oxides of Nitrogen (NOx) emissions.