Engine Control Module Description

The Engine Control Module (ECM) is a hybrid design microprocessor based computer that is the main component of the engine control system. The ECM uses various sensors to optimize fuel/spark/air delivery in order to achieve optimum engine operation. This is done by receiving inputs from engine sensors, processing information and commanding outputs to output devices.

The ECM performs advanced diagnostic tests on different sensors and systems to assure the vehicle is operating properly. Routine checks are run throughout a drive cycle on sensor circuits. The ECM monitors hard circuit failures as well as signals that are out of range during specific driving conditions. When a fault is detected, the ECM will store freeze frame I failure data and set a Diagnostic Trouble Code (DTC).