Engine Control Module

WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The control module system has a computer, Engine Control Module (ECM), to control fuel delivery, timing, and some emission control systems. The control module system monitors a number of engine and vehicle functions and controls the following operations through the Fuel Injection Control Module (FICM): Fuel rail pressure, fuel injector, and fuel injector pulse width. The diesel ECM, located in left front of engine compartment, in the control center of the control module system. See Fig 1 . ECM constantly looks at the information from various sensors, and controls the systems that affect vehicle performance. ECM performs the diagnostic function of the system. ECM can recognize operational problems, alert the driver through the MIL (Service Engine Soon), and store one or more DTCs which identify the problem areas to aid the technician in making repairs.

Fig 1: Locating Engine Control Module

Courtesy of GENERAL MOTORS CORP.