Engine Control Module: Description and Operation

PURPOSE
The control module performs the diagnostic function of the Diesel Electronic Control (DEC) system. It can recognize operational problems, alert the driver through the "Service Engine Soon" light, and store a code or codes, which identify the problem areas to aid the technician in making repairs.

OPERATION
The control module constantly looks at the information from various sensors, and controls the EGR, TCC, and cold advance/glow plug systems.

The control module is designed to process the input information, and then sends the necessary electrical responses to control the DEC system.

LOCATION
The control module is located in the passenger compartment.

NOTE: The control module must be maintained at a temperature below 85°C (185°F) at all times. This is most essential if the vehicle is put through a baking process. The control module will become inoperative if it's temperature exceeds 85°C (185°F). It is recommended that temporary insulation be placed around the control module during the time the vehicle is in a paint oven or other high temperature processes.