EFC System: Description

The Electronic Fuel Control (EFC) system maintains the proper air/fuel ratio during engine operation to maximize fuel economy and minimize emissions. EFC system consists of 10 sensors, the Electronic Control Assembly (ECA) and a combination Air Bleed Control Valve (ABCV)/stepper motor. See Figure . This stepper motor is controlled by the ECA based upon input signals from various sensors, primarily exhaust gas oxygen content. The ECA is also capable of detecting malfunctions within the EFC system, and storing and outputting fault codes for diagnostic purposes.