349E Excavator Machine Electronic Control System System Operation Caterpillar

Engine Speed Control

Illustration 1	g03764891
(1) Switch Panel (23) Machine ECM (70) Monitor (71) Engine ECM

Machine ECM (23) receives the engine speed dial signal from the soft switch panel (1) . The machine ECM then transmits the desired engine speed to the engine ECM (23) . The position of the engine speed dial is indicated on the operator monitor (70) . The machine ECM, engine ECM, and soft switch panel ECM communicates these signals via the CAN data link.

The engine speed dial is a 10-position switch. The selected position is displayed on operator monitor (70) .

The desired engine speed and hydraulic torque settings for each dial position can be changed in Cat ET or through the monitor.

Note: The actual engine RPM and torque output will vary, depending on the setting of the power mode that is selected. The standard mode and economy mode will change to high hydraulic power mode during travel.

Self-Diagnostic Function

The "Machine ECM" (23) is a self-diagnostic component. The "Machine ECM" monitors the inputs and the outputs. The "Machine ECM" monitors the system problems that can occur and system warnings that are generated during the operation of the machine. The "Machine ECM" will display a system warning that is generated via the self-diagnostic function, on the monitor (70) .

Note: A history file is kept for the warnings. The log file contains the time and the number of occurrences of each warning.

Automatic Engine Control (AEC)

Illustration 2	g02738277
(1) Switch Panel (23) Machine ECM (38) "Pump 1 Pressure Sensor" (39) "Pump 2 Pressure Sensor" (45) "Left Travel Pressure Switch" (46) "Right Travel Pressure Switch" (47) "Implement Pressure Switch" (70) Monitor (71) Engine ECM

The "Automatic Engine Control (AEC)" will lower the engine speed if the machine experiences a no load condition for approximately 5 seconds. This process is designed to reduce noise and fuel consumption. When the loaded condition is detected, the engine speed returns to the speed indicated by the setting on the speed dial.

The loaded condition is detected by either the implement pressure switch, the travel pressure switch, or the pump discharge pressure sensors.

Note: Input components related to the tool control system can detect loaded conditions as well.

The operator can select a setting of the AEC using the selection switch on the switch panel. An indicator light on the panel is illuminated when the second setting of the AEC is selected.

Illustration 3	g02161039
AEC Selection Switch

The AEC can be set by the switch on the right console. The indicator of the switch will illuminate during the second setting of the AEC. The second setting of the AEC is available immediately after the engine start switch is turned to the ON position. The AEC can be set in the first stage and the second stage by alternately pressing the switch.

First Setting Of The AEC

The first setting of the AEC will lower the speed of the setting of the engine speed dial by approximately 100 rpm in the "no load" or the "light load" condition.

Second Setting Of The AEC

The second setting of the AEC will reduce the engine speed to a setting equal to the two position on the speed dial, in the "no load" condition.

Note: When the main backup switch is turned to the ON position (Manual), the AEC function is disabled.

One Touch Low Idle

Illustration 4	g02738296
(1) Switch Panel (23) Machine ECM (38) "Pump 1 Pressure Sensor" (39) "Pump 2 Pressure Sensor" (43) "Swing Control Pressure Sensor" (45) "Left Travel Pressure Switch" (46) "Right Travel Pressure Switch" (47) "Implement Pressure Switch" (48) "One Touch Low Idle Switch" (70) Monitor (71) Engine ECM

When the one touch low idle switch is pressed, and the machine is not under a load (all levers and pedals in the neutral position), the engine speed can be lowered by more than the speed of the setting of the second stage of the AEC. When normal operations have resumed, the engine speed for the dial setting will return the corresponding RPM.

The operational condition of the machine is detected by the implement pressure switches of the joystick and the travel switch of the travel pedal .

Start up Of The One Touch Low Idle

The one touch low idle feature will activate during all "stopped" conditions of the implement, swing, travel, and tools. However, when the "One Touch Low Idle" switch is pressed, the control will lower the engine speed. The speed is reduced to a speed dial setting of 2 or approximately 1020 rpm. This control overrides the AEC.

Release Of The One Touch Low Idle

The one touch low idle will be released when any of the following conditions occur:

• The one touch low idle switch (48) is pressed again.

• The "Implement Swing Pressure" sensor is set to the ON position.

• A "Travel Pressure" switch is set to the ON position.

• A pressure switch that is related to a tool is set to the ON position.

The engine speed is different after the switch has been released. The different speed will depend on the conditions of the release.

1. The engine speed will match the setting on the speed dial, when the one touch low idle is released by an operation of the implement.

2. The engine speed is set by the AEC when the one touch low idle switch is used to release the one touch low idle function. The engine speed will be affected by the following conditions:

   1. When the first setting of the AEC is selected, the engine speed will be set to the speed of the first setting of the AEC. The speed is approximately 100 rpm lower than the setting of the engine speed dial.

   2. When the second AEC is selected, the engine speed will be set to the speed of the setting of the second AEC. The speed is approximately 970 rpm.

   3. The engine speed matches the speed setting of the engine speed dial, if the engine speed is lower than the second setting of the AEC. The setting of this speed is not based on a setting of the AEC.

"Engine Speed Protection"

Delayed Engine Shutdown

Illustration 5	g02161067
(23) "Machine ECM" (49) "Key Switch" (58) "Hydraulic Lock Solenoid" (70) "Monitor" (71) "Engine ECM"

The Delayed Engine Shutdown function allows the engine or exhaust system to run at low idle after the key is turned OFF. This function provides a cool down period for the engine or exhaust system.

Illustration 6	g02140333
Key Start Switch

If an immediately stop of the engine is necessary after the key has been turned OFF, turn the key to the emergency stop position (full left position).

Reference For more information on Delayed Engine Shutdown, refer to KENR9509 - 312E, 316E, 320E, 323E, 324E, 329E, 336E, 349E, and 568 Excavators E-Series Monitor, System Operation, "Engine Shutdown Settings Menu"

Engine Idle Shutdown

Illustration 7	g02161107
(23) "Machine ECM" (38) "Pump 1 Pressure Sensor" (39) "Pump 2 Pressure Sensor" (43) "Swing Control Pressure Sensor" (45) "Left Travel Pressure Sensor" (46) "Right Travel Pressure Sensor" (47) "Implement Pressure Switch" (48) "One Touch Low Idle Switch" (49) "Key Switch" (58) "Hydraulic Lock Solenoid" (70) "Monitor" (71) "Engine ECM"

The Engine Idle Shutdown function stops the engine automatically when the machine has been idle for longer than the set time. Before the engine stops, a warning message will be displayed on the Messenger.

Pump Torque Control

Illustration 8	g02738297
(1) "Switch Panel" (23) "Machine ECM" (24) "Straight Travel Pressure Switch" (38) "Pump 1 Pressure Sensor" (39) "Pump 2 Pressure Sensor" (40) "Negative Flow Control 1 Pressure Sensor" (41) "Negative Flow Control 2 Pressure Sensor" (45) "Left Travel Pressure Switch" (46) "Right Travel Pressure Switch" (51) "Power Shift Pressure PRV" (70) "Monitor"

The Machine ECM controls the power shift pressure, based on the position of the speed dial (throttle).

The Machine ECM estimates the load of the main pump by reading the pump discharge pressure and the pressure of the Negative Flow Control pressure. The Machine ECM communicates with the Engine ECM to control the amount of torque required for the main pump.

When the power shift pressure is low, the output of the pump is decreased. When the power shift pressure is high, the torque output of the pump increases. The pump control comes to the constant horsepower control at dial settings of 1 to 9 of the "Engine Speed Dial" and comes to the under speed control at the 10 position of the "Engine Speed Dial".

Under Speed Control

When the speed dial is set to 9 or less, the flow of the pump is controlled with the power shift pressure. This control allows the machine to reach the hydraulic output pressure that corresponds to the position of the speed dial.

When the machine is being used for heavy digging or high speed travel, the speed dial should be set to the 10 position. Setting the speed dial to position 10 allows the power shift pressure for operation of the machine.

Antistall Function

The output of the engine will decrease when inferior fuel is used to operate the machine or when the machine is operated at high altitudes. When the engine output decreases, the engine speed will drop during operation.

When the engine speed is decreased by more than 250 rpm below the rpm for a "no load" condition at a given "Speed Dial" setting, the power shift pressure is decreased in order to reduce the load on the pump.

Regeneration Function

The regeneration function limits the speed of the engine when the boom is moving down. The regeneration function improves the overall fuel efficiency of the machine. The engine speed is reduced to a value that is less than the setting of the engine speed dial. The engine is aided in moving the boom down by the fluid that is routed by the "Boom Down PRV".

The boom lowering operation is detected by the "Boom Lowering Pilot Pressure" Sensor. The machine lift condition is detected by the "Boom Head Pressure" Sensor.

The pilot pressure of the Boom Regeneration valve is controlled according to the desired engine speed or boom lowering operation.

When boom lowering is operated only, the engine speed is reduced according to the operation. When boom lowering is operated with other actuators, the engine speed is reduced according to the flow limitation pressure (NFC) sensor.

When boom lowering is operated only, the main pump flow is reduced according to the operation. When boom lowering is operated with other actuators, the main pump flow is reduced according to the flow limitation pressure (NFC) sensor.

The following chart shows the reduction in engine speed during the downward movement of the boom.

Automatic Travel Speed Change Function

Illustration 9	g02738298
(1) Switch Panel (23) Machine ECM (27) Auxiliary Pedal Electric L/R (38) "Pump 1 Pressure" Sensor (57) "Travel Speed" Solenoid

Illustration 10	g02738301
The location of the button that is used to control the travel speed of the machine.

There are two modes of travel for the machine. The modes are "tortoise" and "rabbit". The control for the travel speed is located on the touch pad that is located to the right of the operator. The panel includes an indicator in order to display the speed function that is active. When the main pump pressure is low, the travel speed is automatically increased to high speed. When the main pump pressure is high and the selected travel speed is high, the travel speed is automatically switched to low speed. When the travel speed is set to tortoise, the travel speed is fixed at the low speed (no change).

Control Of The Hydraulic Oil At Low Temperatures

Illustration 11	g02738303
(1) "Switch Panel" (4) "Hydraulic Oil Temperature" Sensor (23) Machine ECM (51) "Power Shift Pressure PRV"

When the conditions of the climate are cold and the temperature of the hydraulic oil is low, the machine may not operate smoothly.

The hydraulic oil temperature sensor (4) , signals the temperature of the hydraulic oil to the Machine ECM (23) .

The output of the pump will decrease by a small amount under cold conditions. This decrease allows the operations to be smoother until the temperature of the oil rises. When the hydraulic oil temperature sensor has detected an oil temperature below 15 °C (59 °F), the system limits hydraulic pump output pressure to 80% of maximum hydraulic horsepower.

When the hydraulic oil temperature sensor detects an oil temperature that has risen above 20 °C (68 °F), normal control of the machine will begin again.

Protective Function for "Engine Oil Lubricity"

Illustration 12	g02738304
(1) "Switch Panel" (2) "Alternator R Terminal" (23) Machine ECM (43) Alternator (71) Engine ECM (74) "Engine Oil Pressure" Sensor (76) Engine Speed Sensor 1

This function is designed to prevent the engine from starting at a high speed during a condition of low oil pressure. For example, after the engine oil filter is replaced run the engine for a short time in order to fill the oil filter. During this time, the oil pressure of the engine must remain low.

When the engine oil pressure is low, the monitor will display the message "ENG OIL PRESS LOW".

Note: Engine damage may occur if the engine runs at a high setting of the speed dial and the oil pressure of the engine is low.

The engine speed will be limited to the position of 5 on the speed dial , if the engine oil pressure switch is open. The engine will start at the speed of the 5 position.

Swing Brake Operation

Illustration 13	g02738316
(1) Switch Panel (23) Machine ECM (42) "Boom Down Control Pressure" Sensor (43) "Swing Control Pressure" Sensor (47) "Implement Pressure" Switch (56) "Swing Brake " Solenoid (70) Monitor

This machine is equipped with a swing lock system that is hydraulically controlled. The control circuit of the swing lock system provides control for the swing brake .

The "Swing Brake " Solenoid (56) is controlled by the Left Joystick or the Right Joystick (depending on the setup of the operating controls). When the assigned joystick is moved to the NEUTRAL position, the Machine ECM (23) causes the pilot pressure to equalize at the "Swing Brake" Solenoid (56) . The "Swing Brake " Solenoid (56) is energized in order to release the fluid that is contained in the swing control portion of the hydraulic circuit. The release of the pressure by the "Swing Brake" Solenoid releases pressure that is retaining a spring. As a result of the release of pressure, the spring acts to compress a group of braking clutches that act on the swing motor. The "Swing Brake Release" Solenoid (56) is de-energized approximately 6.5 seconds after all levers and pedals are returned to NEUTRAL position.

The swing brake is released immediately on the operation of any of following of these controls: boom, stick, bucket, swing and an attachment.

The "Implement Pressure" Switch (47) , "Boom Down Control Pressure" Sensor (42) , and Swing Control Pressure Sensor (43) are used to monitor the functions listed above.

Illustration 14	g02738319
(1) Switch Panel (9) "Fine Swing Switch" (16) "Fine Swing Solenoid" (23) "Machine ECM" (70) "Monitor"

The fine swing function is designed to open a hydraulic circuit between the ports of the swing motor. This function provides a smooth start and stop operation with of the swing motor. The "Fine Swing" Solenoid (16) is activated by the "Fine Swing" Switch (9) located on the "Switch Panel" (1) .

The Machine ECM detects operation of the fine swing switch in order to release the swing brake.

Tool Control

When an attachment tool is being operated, the engine speed and the pump flow are controlled according to the type of tool. For more information, refer to the appropriate service manual for the tool control of the machine that is being serviced.

Selection Of A Tool

The tools are preprogrammed. The operator selects the tool. The monitor is used to make the selection. The following items are examples of some parameters which can be adjusted in order to accommodate a particular tool:

• The "Engine Speed" dial setting

• Pump flow for one or two pumps

• Pump flow for one or two directions

Engine Speed Economy Mode

To reduce the rate of fuel consumption, the ECO mode limits the engine speed and the torque equivalent of the pump to dial values that are less than usual. The "ECO" mode is selected through the menu options of the monitor. When the "ECO" mode is chosen, the under speed control of the machine cannot be executed. When the tool mode (Tool #1 to #4) is selected, the "ECO" mode is canceled.

The change to "ECO" mode takes place smoothly in approximately 7 seconds together with UP/DOWN.

When the "ECO" mode is selected, the following symbol is displayed at the top of the monitor.

Illustration 15	g02075071

Note: When the "ECO" mode is canceled (at tool option), the symbol is not displayed. When the machine is traveling, the symbol is displayed.

NFC Valve Pump Flow Control

All tools use the flow of the NFC valve control pump. A pressure switch detects the pressure change. A proportional reducing valve restricts the NFC pump flow. A resolver valve selects the higher pressure between the pressure in the control valve and the pressure from the proportional reducing valve. This signal restricts the pump flow to a lower pressure. The main pump flow is then reduced.

This process results in better simultaneous operation of the tool and operation of the implement.

Monitoring System

The monitoring system is an input and an output of the "Machine Control System". The "Machine Control System" communicates back and forth on the "CAN Data Link". The monitoring system consists of the following components: display with numerous screens and menus, keypad, indicators and gauges. These components will be described throughout this manual.

The monitoring system informs the operator of the status of the machine. The monitoring system includes a graphic display that allows the operator to view information that pertains to machine functions. Refer to Illustration 16.

Illustration 16	g02108119
Monitoring System Display (with rear view camera on) (1) Alert Indicator (2) Clock Bar (3) Gauge Indicator (4) Camera View (5) Warning Display Area (6) Multi-Information Area (7) Keypad

Note: The keypad is a multifunction keypad. Symbols for the keypad will be displayed on the Multi-Information Area (6) above the keypad (7) . The symbols will vary depending on the screen that is being displayed.

The keypad is used in order to provide input to the ECM. The keypad is also used to navigate through the menu of the monitoring system.

The view on the monitor screen can be adjusted to show only machine information , machine information, and a view from the camera that is mounted on the rear of the machine , or a full view from the camera that is mounted on the rear of the machine . The camera view on a machine that is equipped with multiple cameras can be preset in the service mode.

Illustration 17	g02738321

The button that is shown in the graphic above is used to change the screen to one of three views:

• A view of the machine functions

• A combined view of the machine functions and the rear view cameras

• A full-screen view of the rear view cameras

A view of the monitoring system will display various warnings and information about the condition of the machine. The monitoring system display has 3 gauges and a number of alert indicators. Each gauge is dedicated to a parameter within a machine system. The monitoring system will allow the user to do the following:

• View system status information

• View parameters

• View service intervals

• Perform calibrations

• Troubleshoot machine systems

Some of the possible parameters of the machine systems are listed: fuel level, engine coolant temperature and hydraulic oil temperature. The gauges receive information from sensors or senders that are connected to the ECM. The ECM uses the information from each sensor input to calculate the value that is shown on the gauges.

The alert indicators will notify the operator of an abnormal condition in a machine system. The ECM uses information from pressure switches, sensors, and other inputs in order to determine when an abnormal condition is present. The ECM will send a message to the monitoring system display. Then, the monitoring system will display a pop-up alert indicator for the machine system with the abnormal condition.

See Service Manual, KENR9509, "Monitoring System"