F7037 Force NUT, 7/8 - 14

Electronic Controls
The 3176C/3196 and 3406E Marine Engines electronic system consists of the Electronic Control Module (ECM) and engine sensors. The ECM is the computer which controls the engine operating parameters. The Personality Module in the ECM contains the software which controls how the ECM behaves (the personality module stores the operating maps that define power, torque curves, rpm, etc). The injection pump, fuel lines and fuel injection nozzles used in mechanical engines have been replaced with an electronic unit injector in each cylinder. A solenoid on each injector controls the amount of fuel delivered by the injector. The Electronic Control Module (ECM) sends a signal to each injector solenoid to provide complete control of the engine.Engine Governor
The Electronic Control on the engine serve as the engine governor. The Electronic Control determines when and how much fuel to deliver to the cylinders based on the actual and desired conditions at any given time.The governor uses the Throttle Position Sensor to determine the desired engine rpm and compares this to the actual engine rpm determined through the Engine Speed/Timing Sensor. If desired engine rpm is greater than the actual engine rpm, the governor injects more fuel to increase engine rpm. Timing Considerations
Once the governor has determined how much fuel is required, it must next determine when to inject the fuel. Injection timing is determined by the ECM after considering input from the Coolant Temperature Sensor, Inlet Air Manifold, Temperature Sensor, Atmospheric Pressure Sensor, And Inlet Air Manifold (Boost) Pressure Sensor.The ECM determines where top center on cylinder number one is located from the Engine Speed/Timing Sensor signal. The ECM decides when injection should occur relative to top center and provides the signal to the injector at the desired time. The ECM adjusts timing for best engine performance, fuel economy and white smoke control. Actual or Desired Timing cannot be viewed with an Electronic Service Tool. Fuel Injection
The ECM controls the amount of fuel injected by varying signals to the injectors. The injectors will pump fuel only if the injector solenoid is energized. The ECM sends a high voltage signal to energize the solenoid. By controlling the timing and duration of the high voltage signal, the ECM can control injection timing and the amount of fuel injected.The Personality Module inside 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 air/fuel ratio for emissions control. 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 power rating of the engine and rpm. It is similar to the rack stops and torque spring on a mechanically governed engine. It provides power and torque curves for a specific engine family and rating. All of these limits are determined at the factory in the Personality Module and cannot be changed.
Figure 1.1 - Fuel InjectionCustomer Parameters Effect on Engine Governing
A unique feature with Electronic Engines is the Customer Specified Parameters. These parameters allow the engine owner to fine tune the ECM for engine operation to accommodate the typical or specific usage of the engine.Many of the Customer Parameters provide additional restrictions on the action the ECM will take in response to the operators' input. For example, the Top Engine Limit is an rpm limit the ECM uses as a maximum rpm for fuel delivery to the injectors. The ECM will not fuel the injectors above this rpm.Some parameters are intended to notify the operator of potential engine damage such as Engine Monitoring Parameters. Other parameters are provided to enhance the engine installation or provide engine operating information to the engine owner.Engine Monitoring
Caterpillar provides a factory installed Engine Monitoring System. The Caterpillar Engine Monitoring System monitors engine oil pressure, coolant temperature, inlet air manifold, air temperature, coolant level, fuel temperature and fuel pressure.Caterpillar Engine Monitoring can be programmed to different modes (OFF, and DERATE). The Coolant Temperature Sensor, Oil Pressure Sensor and Coolant Level Sensor (if enabled) will operate in the Engine Monitoring Mode selected.For example, if DERATE was selected, the engine will derate engine power if the Coolant Temperature Sensor, Oil Pressure Sensor or Coolant Level Sensor (if enabled) detect conditions exceeding acceptable limits. The Warning Lamp/Alarm will be ON.Caterpillar Engine Monitoring OFF Operation
If Caterpillar Engine Monitoring is programmed to OFF, the ECM will not flag any of the sensor values and disables those diagnostics associated with Engine Monitoring even though the level or conditions are exceeded which could cause the ECM to take Engine Monitoring action.The ECM still uses these sensors for normal engine operation, such as the Coolant Temperature Sensor for Cold Mode operation.Caterpillar Engine Monitoring Operation
If the system is programmed to , the ECM turns on the Warning Lamp and logs the event to indicate a problem has been detected by the Engine Monitoring System. No further ECM or engine action occurs if the ECM is programmed to . The Oil Pressure Sensor can not be programmed to , while the Coolant Temperature Sensor operates in a DERATE mode.Caterpillar Engine Monitoring DERATE Operation
If the system is programmed to DERATE, the ECM begins by flashing or activating the Warning Lamp. If the problem is due to a Low Coolant Level, Low Oil Pressure, High Inlet Air Manifold Temperature, High Coolant Temperature or High Fuel Temperature condition, the ECM will turn the Warning Lamp ON.When Very Low Oil Pressure, Very Low Coolant Level, or a High or Very High Coolant Temperature are detected, DERATE Mode begins by flashing the Warning Lamp. Whenever the Warning Lamp is flashing, the ECM is limiting (derating) the engine power.For High and Very High Coolant Temperature, or Very Low Coolant Level, the ECM reduces available power. If the detected condition is Very Low Oil Pressure, power and engine rpm are limited. This derating of engine performance is provided to the operators so action can be taken to avoid engine