5034842 JOHNSON KEY, IMPELLER

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. Actual engine rpm is detected by the engine speed/timing sensor.Fuel Injection
The engine ECM controls the timing and the duration 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.Engine Starting and Stopping Procedures
Engine Starting Sequence
1) The generator control module will receive one of the following start signals:
The operator places the control in the RUN mode.
The operator places the control in the AUTO mode and the remote initiate input becomes active.
The operator places the control in the AUTO mode and a start command is sent via the data link.2) The generator control module performs the following system checks:
No system faults are present.
All previous shutdown faults have been reset.
The engine is not already running.
If the prelube (if equipped) is not complete, the generator control module will not crank the engine.3) The generator control module begins the following cranking sequence:
Activate the Starting Motor Relay (SMR).
A start signal is sent to the engine ECM via the Cat Data Link and the fuel control relay is activated.4) The generator control enables cranking the engine until the cycle crank time reaches the setpoint for total crank time or until the engine starts.5) The generator control module deactivates the SMR when the engine speed reaches the setpoint for crank terminate speed.Engine Stopping Procedure
1) The generator control module receives one of the following engine stop signal:
The operator places the control in the STOP mode.
The operator places the control in the AUTO mode and the remote initiate input becomes inactive.
The generator control module begins the cooldown period. Place the generator control in the STOP mode in order to bypass the cooldown . "PRESS ENTER TO BYPASS" and "PRESS ESCAPE TO CONTINUE" will be shown on the display. 2) After the cooldown period, the generator control module sends a shutdown signal to the engine ECM. The engine ECM deactivates the fuel control relay which shuts down the engine.Block Diagram for the 3500B Engine
Illustration 1 g01189813
Typical components
Illustration 2 g01189857
Typical block diagram for the generator control
Illustration 3 g01189902
Typical block diagram for communications
Location Of The 3512B and 3516B Engine Sensors
Illustration 4 g01145402
Typical 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/P1 Location Of The 3512B and 3516B Engine Sensors
Illustration 5 g01145414
Typical 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 switch Location Of The 3512B and 3516B Engine Sensors
Illustration 6 g01145410
Typical front and rear view
(19) Connector for the engine fan speed sensor
(20) Turbocharger outlet pressure sensor
(21) Rear aftercooler temperature sensor Location Of The 3508B Engine Sensors
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