Engine Control Module (ECM) Description: Notes
| Callout | Component Name |
|---|---|
| 1 | Engine Control Module (ECM) |
| 2 | Fuel Injector Multi-Way Harness Connector |
| 3 | Ignition Coil Ground |
| 4 | ECM Ground |
| 5 | Throttle Body Assembly |
| 6 | ECM Connector C1 |
| 7 | ECM Connector C2 |
The engine control module (ECM) (1) interacts with many more emission related components and systems, and monitors emission related components and systems for deterioration. OBD II diagnostics monitor the system performance and a diagnostic trouble code (DTC) sets if the system performance degrades.
The malfunction indicator lamp (MIL) operation and the DTC storage are dictated by the DTC type. A DTC is ranked as a Type A or Type B if the DTC is emissions related. Type C is a non-emissions related DTC.
The ECM is in the engine compartment. The ECM is the control center of the engine controls system. The ECM controls the following components:
- The fuel injection system
- The ignition system
- The emission control systems
- The on-board diagnostics
- The A/C and fan systems
- The throttle actuation control (TAC) system
The ECM constantly monitors the information from various sensors and other inputs, and controls the systems that affect the vehicle performance and the emissions. The ECM also performs diagnostic tests on various parts of the system. The ECM can recognize operational problems and alert the driver via the MIL. When the ECM detects a malfunction, the ECM stores a DTC. The condition area is identified by the particular DTC that is set. This aids the technician in making repairs.