24220 Mercury SCREW, (.190-24 x .19)

Electronic Controls
Electronic Control Module
The ECM consists of two main components, the control computer (hardware) and the flash file. The control computer consists of a microprocessor and of electronic circuitry. The flash file contains the engine's operational characteristics. The operating maps influence the engine's performance.Engine Governor
The engine ECM governs engine speed. The engine ECM and the flash file work together by controlling the amount of fuel that is delivered by the injectors. Desired engine rpm is determined by the throttle position sensor signal and by certain sensor readings. Diagnostic codes may derate the engine. Actual engine rpm is measured by the engine speed/timing sensor.Fuel Injection
The engine ECM controls the timing, the duration, and the pressure of the fuel that is injected. The engine ECM varies the signals to the fuel injectors. Fuel is injected only while an injector solenoid is energized by a 105 volt signal from the engine ECM. The timing of the injection signal determines the engine timing. The length of the injection signal determines engine speed. By controlling the timing and duration of the 105 volt signal, the ECM controls the engine speed.Cold Mode Operation
The engine ECM uses cold mode operation in order to reduce white smoke during engine warm-up. The engine ECM cuts out the injectors one at a time in order to determine if the cylinder is firing. If the cylinder is firing correctly, the engine ECM leaves the injector on. If the cylinder is not firing, the engine ECM will leave the injector off. This will increase startability and this will reduce warm up time.Cold mode is activated whenever the engine coolant temperature falls below a predetermined value. Cold mode remains active until the engine has warmed or a time limit is exceeded. Fuel Ratio Control Limit (FRC)
The flash file inside the engine ECM sets certain limits on the amount of fuel that can be injected. The FRC is a limit that is based on the boost pressure. The boost pressure is calculated as the difference in pressure between atmospheric pressure and turbocharger outlet pressure. The FRC is used to control the air/fuel ratio for control of emissions. When the engine ECM senses a higher boost pressure, the engine ECM increases the FRC. A higher boost pressure indicates that there is more air in the cylinder. When the engine ECM increases the FRC, the engine ECM allows more fuel into the cylinder.Rated Fuel Position
The rated fuel position is a limit that is based on the power rating of the engine. The rated fuel position is similar to the rack stops and the torque spring on a mechanically governed engine. The rated fuel position determines maximum power and torque values for a specific engine family and for a specific rating. The rated fuel position is programmed into the flash file.Block Diagram of Electronic Governor
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Typical exampleEngine Wiring Diagram
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Typical exampleEngine Wiring Diagram
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Typical exampleLocation Of The 3516B Engine Sensors
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Left side view (1) Left turbocharger inlet pressure sensor (2) Exhaust temperature sensor (LH) (3) Connector for the CAN data link (4) Engine ECM (5) Engine speed/timing sensor (6) Unfiltered engine oil pressure sensor (7) Low oil level switch (8) Very low oil level switch (9) Filtered engine oil pressure sensor (10) Atmospheric pressure sensor (11) ECM connector J2/P2 (12) ECM connector J1/P1Location Of The 3516B Engine Sensors
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Right side view (13) Connector for the timing calibration sensor (14) Exhaust temperature sensor (RH) (15) Crankcase pressure sensor (16) Connector for the continuous oil renewal solenoid (17) Electric fuel priming pump (18) Coolant flow switchLocation Of The 3516B Engine Sensors
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Front and rear view (19) Connector for the engine fan speed sensor (20) Turbocharger outlet pressure sensor (21) Rear aftercooler temperature sensor