09300-03180 PUMP ASSY, INJECTI Calibration Data

Electronic Controls
The 3176 Diesel Truck Engine controller consists of two main components: the Electronic Control Module (ECM) and the Personality Module. The ECM is the computer and the personality module is the software for the computer (the personality module also stores the operating maps that define horsepower, torque curves, rpm, etc). The two work together (along with sensors to "see" and solenoid/injectors to "act") to control the engine. Neither one can do anything by itself.The ECM determines a "desired rpm" based on the throttle signal, vehicle speed signal (only while in cruise), PTO switches (only while in cruise or PTO) and certain diagnostic codes. The ECM then maintains the desired engine rpm by sensing actual engine rpm and deciding how much fuel to inject in order to achieve the desired rpm. Fuel Injection
The ECM controls the amount of fuel injected, by varying signals to the injectors. The injectors will inject fuel ONLY if the injector solenoid is energized. The ECM sends a 100 volt signal to the solenoid to energize it. By controlling the timing and duration of the 100 volt signal, the ECM can control injection timing and the amount of fuel injected.The ECM sets certain limits on the amount of fuel that can be injected. "FRC Fuel Pos" is a limit based on boost pressure to control the fuel-air ratio, for emissions control purposes. When the ECM senses a higher boost pressure (more air into cylinder), it increases the "FRC Fuel Pos" limit (allows more fuel into cylinder). "Rated Fuel Pos" is a limit based on the horsepower rating of the engine. It is similar to the rack stops and torque spring on a mechanically-governed engine. It provides horsepower and torque curves for a specific engine family and rating. All of these limits are programmed by the factory into the Personality Module and are not programmable in the field.Injection timing depends on engine rpm, load and other operation factors. The ECM knows where top-dead-center of cylinder number one is from the signal provided by the engine Speed/Timing Sensor. It decides when injection should occur relative to top-dead-center and provides the signal to the injector at the desired time.Under certain conditions, the 3176 Engine may intentionally operate on just three cylinders. This feature is called "Three Cylinder Cutout" and occurs when the engine is operated under no load, at high rpm (when signals to the injectors are of very short duration). Under these conditions, the ECM does not inject fuel into cylinders 4, 5 and 6. This allows for more precise fuel metering to cylinders 1, 2 and 3. The accompanying change in feel and sound of the engine should not be diagnosed as an engine problem. When more power is needed, all six cylinders will be fueled and full power delivered.Programmable Parameters
Certain parameters that affect 3176 Diesel Truck Engine operation may be changed through electronic service tools (either the ECAP or DDT). The parameters are stored in the ECM and passwords are used to prevent unauthorized