Diesel CEC System - W/External EGR: Description
The Diesel Electronic Control (DEC) system is used on 4.3L V6 and 5.7L V8 diesel engines (except 4.3L V6 diesel with internal EGR). A different DEC system is used on the 4.3L V6 diesel engine equipped with internal EGR. See the DIESEL INT/EGR SYSTEM article in this section (if applicable).
The DEC system monitors various engine functions to electronically control Exhaust Gas Recirculation (EGR) system, injection pump timing, reduce emissions and improve driveability at different altitudes. The diesel Electronic Control Module (ECM) is the "brain" of the system.