COVER AS 4784051 - Caterpillar

Component Description
Engine Control Module (ECM)
Engine Control Module (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. Then, the ECM uses this data in order to adjust the fuel delivery, injection pressure, and injection timing. The ECM contains programmed performance maps (software) in order to define horsepower, torque curves, and rpm. This software is commonly called the personality module.The engine does not have a replaceable personality module. The personality module is a permanent part of the ECM. The personality module for the engine can be reprogrammed by Caterpillar Electronic Technician (ET).ECM logs faults of engine performance. Also, the ECM can run several diagnostic tests automatically when the ECM is used with an electronic service tool such as the Cat ET.Priming Pump
The electric priming pump forces the air that is in the fuel out of the system through the orifice on the regulator. Priming usually takes place after servicing the fuel system such as changing the fuel filter. This mode can also occur when the engine has not run for a long period. When the fuel system has air trapped in the fuel filters, lines, and other fuel system components, the engine could experience difficulty starting. The electric priming pump is turned on manually or the electric priming pump is turned on automatically in order to prime the system. The time for priming depends on the size of the fuel system. Nominal time of priming is about 30 seconds. This value varies by applications.Fuel Transfer Pump
Illustration 2 g01945334
(1) High-pressure fuel pump (2) Fuel transfer pump (3) Low-pressure fuel inlet (4) Low-pressure fuel outletFuel transfer pump (2) is a pump that produces low pressure, high volume to pull fuel from the tank and through the primary fuel filter. Then, the pump sends the fuel through the secondary filter and the tertiary filter on the way to the high-pressure fuel pump. The high-pressure fuel pump feeds the injectors. The transfer pump is mounted on the back of high-pressure fuel pump (1) . The fuel transfer pump is a variable gear pump, that is driven by the shaft of the high-pressure fuel pump. A relief valve in the fuel transfer pump limits the outlet pressure to 1009 kPa (146 psi).High-pressure fuel pump
Illustration 3 g01945336
(1) High-pressure fuel pump (5) Solenoids for the high-pressure fuel pump (6) High-pressure fuel outlet (7) Fuel return to tank (8) Fuel from fuel filter (9) Inlet for engine oilHigh-pressure fuel pump (1) pressurizes the fuel to 190 MPa (27550 psi). The high-pressure fuel pump is located at the left front corner of the engine. The high-pressure fuel pump uses electronic solenoids and RPM from the engine to pressurize the fuel.
Illustration 4 g01945338
Cross section of the high-pressure fuel pump (2) Fuel transfer pump (10) Electronic controlled metering valves (11) Camshaft roller tappet (12) Camshaft with three lobesQuill Tube
Illustration 5 g01945355
Side view (13) Quill tube (14)