910903-6512 Tohatsu SCREW

Electronic Controls
Electronic Control Module
The ECM consists of two main components, the control computer (hardware) and the Personality Module (software). The control computer consists of a microprocessor and electronic circuitry. The Personality Module is the software for the control computer which contains operating maps that define power and torque curves.The ECM governs engine speed. Desired engine speed is determined by the throttle position sensor signal and certain sensor readings. Diagnostic codes may derate the engine. Actual engine speed is determined by the Engine Speed/Timing signal.Fuel Injection
The ECM controls the timing of the injectors. The ECM varies the signals to the injectors. Fuel is injected ONLY while an injector solenoid is energized by a 105 volt signal from the ECM. By controlling the timing and duration of the 105 volt signal, the ECM controls the fuel injection timing, the quantity of fuel and the desired engine speed.Injection timing depends on engine speed, load, and other operational factors. The ECM detects the top center of each cylinder. The ECM sends an injection signal at the desired time. The ECM limits engine power during cold mode operation. The FRC Fuel Position is increased when the ECM senses a higher Turbocharger Compressor Outlet Pressure. This will allow more fuel into the cylinder. The Rated Fuel Position is a limit that is based on the engine power rating. This is similar to the rack stops and the torque spring on a mechanically governed engine. The Rated Fuel Position provides power. The Rated Fuel Position provides the power curves and the torque curves for a specific engine family.Cold Mode
The ECM modifies the injection timing and the ECM cuts out the cylinders. 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. The ECM is programmed at the factory which limits the quantity of fuel that can be injected. The FRC Fuel Position controls the fuel limit for exhaust smoke. The FRC is based on the maximum allowable fuel to air ratio. Cold mode is activated when the coolant temperature is below 63 °C (145 °F).Engine Wiring Diagram
Illustration 1 g00752125
Location Of The Engine Sensors
Illustration 2 g00758093
Left Side View (1) Filtered fuel pressure sensor (2) Aftercooler temperature sensor (3) Left air shutoff solenoid (4) Left turbocharger inlet pressure sensor (5) Unfiltered fuel pressure sensor (6) Left exhaust temperature sensor (7) Service tool connector (8) Secondary engine speed/timing sensor (9) Primary engine speed/timing sensor (10) Machine interface connector (11) Unfiltered engine oil pressure sensor (12) Filtered engine oil pressure sensorLocation Of The Engine Sensors
Illustration 3 g00758094
Right Side View (13) Right turbocharger inlet pressure (14) Right air shutoff solenoid (15) Right exhaust temperature sensor (16) Timing calibration sensor (17) Crankcase pressure sensorLocation Of The Engine Sensors
Illustration 4 g00758095
Front View (18) Coolant temperature sensor (19) Turbocharger compressor outlet pressure sensor (20) Optional Engine oil temperature sensor (21) Atmospheric pressure sensor (22) Engine control module (ECM)Electronic Governor
Illustration 5 g00752115
Electronic Governor