TM 9-6115-729-24
0003
HYDRAULIC ELECTRONIC UNIT INJECTOR (HEUI) FUEL SYSTEM - Continued
Electronic Control Module (ECM)
The ECM computer electronically controls engine performance. The ECM uses engine performance data
gathered by several sensors to make adjustments to the fuel delivery, injection pressure and injection timing. The
ECM contains programmed performance maps (software) to define horsepower, torque curves and rpm. This
software is commonly called the personality module. The ECM logs faults of engine performance. The ECM can
diagnose problems with itself and the sensors and sensed values input to the module. When a problem is
