DFI System Theory/Operation: Description

The Digital Fuel Injection (DFI) system combines engine control, fuel metering and emission monitoring into a computer- controlled system. The Electronic Control Module (ECM) is the "brain" of the DFI system. The ECM is a digital electronic computer which receives and processes engine data, computes and interprets engine information, and sends instructions to various components. It provides fuel efficient operation with reduced exhaust emissions.

All models are also equipped with a Body Control Module (BCM) that is used to control various vehicle body functions based upon data sensors and switch inputs. The ECM and BCM exchange information to maintain efficient operation of all vehicle functions. This transfer of information gives the BCM control over the ECM's self-diagnostic capabilities as well as its own.