Engine Control Module Description: Notes

The engine control module (ECM) is the control center of the engine controls system. The ECM constantly monitors information from various sensors and controls the systems that affect vehicle performance and emissions. The ECM also performs diagnostic tests on various parts of the system. The ECM can detect operational malfunctions and alert the driver via the malfunction indicator lamp (MIL). When the ECM detects a malfunction, it stores a diagnostic trouble code (DTC). The condition is identified by the particular DTC that is set. This aids the technician in making repairs.