PLATE AS 4525532 - Caterpillar

Standard Diesel Injection
Electronic Controls
The electronic system consists of the following components: the ECM, the Mechanically Actuated Electronically Controlled Unit Injectors (MEUI), the wiring harness, the switches, and the sensors. The ECM is the computer. The flash file is the software for the computer. The flash file contains the operating maps. The operating maps define the following characteristics of the engine:
Horsepower
Torque curvesThe ECM determines the timing and the amount of fuel that is delivered to the cylinders. These decisions are based on the actual conditions and/or the desired conditions at any given time.The ECM compares the desired engine speed to the actual engine speed. The actual engine speed is determined through a signal from the engine speed/timing sensor. The desired engine speed is determined through the following items:
Throttle position sensor
Other input signals from sensors
Certain diagnostic codesIf the desired engine speed is greater than the actual engine speed, the ECM injects more fuel to increase the actual engine speed.Fuel Injection
The ECM controls the amount of fuel that is injected by varying the signals to the injectors. The injectors will pump fuel only if the injector solenoid is energized. The ECM sends a high-voltage signal to the solenoid. This high-voltage signal energizes the solenoid. By controlling the timing and the duration of the high-voltage signal, the ECM can control injection timing and the ECM can control the amount of fuel that is injected.Once the ECM determines the amount of fuel that is required, the ECM must determine the timing of the fuel injection. The ECM determines the top center position of each cylinder from the engine speed/timing sensor's signal. The ECM determines when fuel injection should occur relative to the top center position and the ECM provides the signal to the injector at the desired time. The ECM adjusts timing for optimum engine performance, for optimum fuel economy, and for optimum control of white smoke.Programmable Parameters
Certain parameters that affect the engine operation may be changed with the Cat® Electronic Technician (ET). The parameters are stored in the ECM, and some parameters are protected from unauthorized changes by passwords.Passwords
Several system configuration parameters and most logged events are protected by factory passwords. Factory passwords are available only to Caterpillar dealers. Refer to Troubleshooting, "Factory Passwords" for additional information.Dynamic Gas Blending (DGB)
The DGB engine kit automatically adjusts to changes in incoming gas fuel quality and pressure allowing diesel engines to run on a wide variety of fuels. The kit has an engine electrical and protection system that protects the engine from excessive heat and detonation during the combustion process. To maintain detonation protection and engine life, it is necessary to regulate the flow of gaseous fuel. Through continuous engine monitoring, the DGB engine kit achieves maximum substitution of gaseous fuel while maintaining engine life.The key components of the DGB engine electrical and protection systems are:
A4 Engine ECM
In Cylinder Pressure Sensor (ICPS) ECM
ICPS
Exhaust temperature sensors
Electronic Modular Control Panel (EMCP) 4.3/4.4Engine Control Module (ECM)
All engine functions are controlled by an integrated A4:E4 ECM. The ECM monitors