SHIM 8S6049 - Caterpillar

The engine is designed for electronic control of most engine operating functions. The electronic system consists of an Electronic Control Module (ECM), wiring harnesses, switches, sensors, and electronic unit injectors (EUI). The ECM monitors parameters during engine operation.Electronic Controls
Electronic Control Module
The ECM consists of two main components, the control computer (hardware) and the personality module (software). The control computer consists of a microprocessor and of electronic circuitry. The personality module is the software for the control computer which contains operating maps that define power and torque curves.The ECM governs engine speed. Desired engine rpm is determined by the throttle signal from the speed control and certain sensor readings. Diagnostic codes may derate the engine. Actual engine rpm is determined by the engine speed/timing signal.Fuel Injection
The injector solenoids are energized by a 105 volt signal from the ECM. The ECM controls the amount of fuel that is injected by varying the signals to the injector solenoids. The injectors will pump fuel only if the injector solenoid is energized. By controlling the timing and duration of the 105 volt signal, the ECM controls the fuel injection timing, the quantity of fuel and the desired engine rpm.The ECM limits engine power during "Cold Mode" operation and the ECM modifies injection timing during "Cold Mode" operation. "Cold Mode" operation provides the following benefits:
Increased cold weather starting capability
Reduced warm-up time
Reduced white smoke"Cold Mode" is activated whenever the engine coolant temperature falls below a predetermined value. "Cold Mode" remains active until the engine temperature rises above a predetermined value.The personality module inside the ECM sets certain limits on the amount of fuel that can be injected. The Fuel Ratio Control (FRC) is used to control the air/fuel ratio for control of emissions. The FRC is a limit that is based on the turbocharger outlet pressure. A higher turbocharger outlet pressure indicates that there is more air in the cylinder. When the ECM senses a higher turbocharger outlet pressure, the ECM increases the FRC. When the ECM increases the FRC, the ECM allows more fuel into the cylinder. The FRC is programmed into the personality module at the factory. The FRC cannot be changed.The Rated Fuel Position is a limit that is based on the engine power rating. This is similar to the rack stops and the torque spring on a mechanically governed engine. The Rated Fuel Position provides the power curves and the torque curves for a specific engine family. The "Rated Fuel Limit" is programmed into the personality module at the factory. The "Rated Fuel Limit" cannot be changed.Engine with Electronic Monitoring System and without Loadshare Unit
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Engine with EMCP II and without Loadshare Unit
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Engine Electronic System
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Location of the Engine Components for 3512B and 3516B Engines
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Typical left side view (1) Unfiltered fuel pressure sensor (2) Filtered fuel pressure sensor (3) Filtered oil pressure sensor (4) Left exhaust temperature sensor (5) Left air shutoff solenoid (6) Left turbocharger compressor inlet pressure sensor (7) Coolant temperature sensor (8) Engine speed/timing sensor (9)