Electronic Engine Control (EEC) System

ELECTRONIC ENGINE CONTROL (EEC) SYSTEM

Overview
The EEC system provides optimum control of the engine through the enhanced capability of the powertrain control module (PCM). The EEC system also has an on board diagnostic (OBD) monitoring system with features and functions to meet federal regulations on exhaust emissions.

The EEC system has 2 major divisions: hardware and software. The hardware includes the PCM, sensors, switches, actuators, solenoids, and interconnecting terminals. The software in the PCM provides the strategy control for outputs (engine hardware) based on the values of the inputs to the PCM. EEC hardware and software are described.

This contains detailed descriptions of the operation of EEC system input sensors and switches, output actuators, solenoids, relays and connector pins (including other power ground signals).

The PCM receives information from a variety of sensor and switch inputs. Based on the strategy and calibration stored within PCM, the PCM generates the appropriate output. The system is designed to minimize emissions and optimize fuel economy and driveability. The software strategy controls the basic operation of the engine, provides the OBD strategy, controls the malfunction indicator lamp (MIL), communicates to the scan tool over the data link connector (DLC), allows for flash electrically erasable programmable read only memory (EEPROM), provides idle air and fuel trim, and controls failure mode effects management (FMEM).

Modifications to OBD Vehicles
Modifications or additions to the vehicle may cause incorrect operation of the OBD system. Non-factory anti-theft systems, cellular telephones, and radios must be carefully installed. Do not install these devices by tapping into or running wires close to the powertrain control system wires or components.