Electronic Controls
Electronic Control Module
The ECM consists of two main components, the control computer (hardware) and the Personality Module (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 Personality Module 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 signal.
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.
Injection timing depends on the following conditions: desired engine rpm and load. The ECM detects the top center of each cylinder. The ECM sends an injection signal at the desired time.
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 of the personality module at the factory.
Block Diagram of Electronic Governor
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| Illustration 1 | g00928043 |
Typical example | |
Engine Wiring Diagram
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| Illustration 2 | g00928044 |
Typical example | |
Engine Wiring Diagram
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| Illustration 3 | g00916634 |
Typical example | |
Location Of The 3516B Engine Sensors
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| Illustration 4 | g00916938 |
Right side view (1) Rear aftercooler temperature sensor (2) Right exhaust temperature sensor (3) Timing calibration sensor (4) Crankcase pressure sensor (5) Connector for the Continuous oil renewal solenoid (6) Coolant flow switch | |
Location Of The 3516B Engine Sensors
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| Illustration 5 | g00916941 |
Left side view (7) Coolant temperature sensor (8) Jacket water temperature sensor (9) Connector for the left turbocharger inlet pressure sensor (10) Connector for the fan control solenoid (11) Left exhaust temperature sensor (12) Fuel filter differential pressure switch (13) Unfiltered oil pressure sensor (14) Low oil level switch (15) Filtered oil pressure sensor (16) ECM ground bolt (17) Engine speed/timing sensor | |
Location Of The 3516B Engine Sensors
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| Illustration 6 | g00916942 |
Front and rear view (18) Connector for the right turbocharger inlet pressure sensor (19) Turbocharger outlet pressure sensor (20) Aftercooler temperature sensor (21) ECM connector J2/P2 (22) ECM connector J1/P1 (23) Electronic control module (ECM) (24) Atmospheric pressure sensor (25) Speed sensor connector for the fan clutch (26) Machine interface connectors (1) Rear aftercooler temperature sensor (7) Coolant temperature sensor (12) Fuel filter differential pressure switch | |