User Manual

ECM
The ECM is located on the left side of the engine. The ECM is a powerful computer that provides total
electronic control of engine performance. The ECM uses data from engine performance that is gathered by
several sensors. The ECM uses this data in order to make adjustments to the fuel delivery, injection pressure
and injection timing. The ECM contains programmed performance maps (software) in order to define
horsepower, torque curves and rpm.
The ECM logs faults of engine performance. The ECM is also capable of running several diagnostic tests
automatically when the ECM and Caterpillar Electronic Technician (ET) are used together.
Unit Injector Hydraulic Pump
The unit injector hydraulic pump is a variable delivery piston pump. The unit injector hydraulic pump uses a
portion of the engine lubrication oil. The unit injector hydraulic pump pressurizes the engine lubrication oil to
the injection actuation pressure that is required in order to power the HEUI injectors.