Impala V8-5.3L VIN C (2006)
Engine Control Module: Description and Operation
Displacement on Demand (DOD) System
ENGINE CONTROL MODULE (ECM)
The engine control module (ECM) is responsible for the management and control of all engine functions. Each ECM comes equipped with a specific set
of software/calibrations designed for that engine and vehicle application. The ECM will determine engine operating parameters, based upon information
from a network of switches, sensors, modules and communication with other controllers located throughout vehicle. Internal to the ECM is an integrated
circuit device called a low-side driver. The low-side driver is designed to operate internally, like an electronic switch. An individual low-side driver
controls each valve lifter oil manifold (VLOM) solenoid. When enabling conditions for V4 mode are met, the ECM will command the low-side driver to
ground each VLOM solenoid control circuit, in firing order sequence. Internal to the low-side driver is a fault detection circuit, which monitors the
solenoid control circuit for an incorrect voltage level. If an incorrect voltage level, such as an open, high resistance, short to ground, or short to power, is
detected, the low-side driver, along with the fault detection circuit, will communicate the condition to the central processor in the ECM. The ECM will
then command a return to V8 mode, set a corresponding DTC, and illuminate the malfunction indicator lamp (MIL) on the instrument panel.
