Engine Control Module (ECM) Description: Powertrain

The powertrain has electronic controls to reduce exhaust emissions while maintaining excellent driveability and fuel economy. The engine control module (ECM) is the control center of this system. The ECM monitors numerous engine and vehicle functions. The ECM constantly looks at the information from various sensors and other inputs, and controls the systems that affect vehicle performance and emissions. The ECM also performs the diagnostic tests on various parts of the system. The ECM can recognize operational problems and alert the driver with the malfunction indicator lamp (MIL). When the ECM detects a malfunction, the ECM stores a diagnostic trouble code (DTC). The problem area is identified by the particular DTC that is set. Review the components and wiring diagrams in order to determine which systems are controlled by the ECM.

The following are some of the functions that the ECM controls:

• The engine fueling
• The ignition control (IC)
• The knock sensor (KS) system
• The evaporative emissions (EVAP) system
• The generator
• The A/C clutch control
• The cooling fan control