LHPH 320 330 Electronic Control Unit

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MEETING GUIDE 621

SLIDES AND SCRIPT

AUDIENCE

Level II - Service personnel who understand the principles of machine systems operation, diagnostic equipment, and procedures for testing and adjusting.

CONTENT

This presentation contains the information and visuals necessary to develop a Level II course of instruction on the Electronic Control Unit (ECU) for the 320, 320L, 320N, 330, and 330L Hydraulic Excavators. Emphasis is placed on explaining how the ECU and Monitor Panel function. The Data and Calibration Modes of the system are also explained in detail.

OBJECTIVES

After learning the information in this presentation, the serviceman will be able to: 1. locate and identify the major components of the ECU and monitor panel system; 2. identify all input and output signals for the ECU and monitor panel;

3. explain the function and operation of each major component; and

4. explain and demonstrate how to access the built-in diagnostic procedures.

REFERENCES

320, 320L and 320N Excavators Service Manual (3116 Engine with Bent Axis Pump) SENR5450 320, 320L and 320N Excavators Service Manual (3066 Engine with Swashplate Pump) SENR5465 320, 320L and 320N Excavators Hydraulic and Electronic Systems Testing and Adjusting SENR5473

320, 320L and 320N Excavators Parts Book SEBP2034

330 and 330L Excavators Service Manual SENR5490

330 and 330L Excavators Hydraulic and Electronic Systems Testing and Adjusting SENR5496

330 and 330L Excavators Parts Book SEBP2171

PREREQUISITES

Cat Hydraulics Course (or equivalent) SEGV2519

STMG 546 "Graphic Fluid Power Symbols" SESV1546

STMG 584 "Electronic Power Unit Control for E-Series Hydraulic Excavators" SESV1584

SUPPLEMENTARY TRAINING MATERIAL

STMG 619 "320/330 Hydraulic Excavator--Pumps and Pump Controls" SESV1619 STMG 620 "320/330 Hydraulic Excavator--Hydraulic Systems Operation" SESV1620

Estimated Time: 3 Hours Visuals: 58 (2 X 2) Slides

Serviceman Handouts: 4 line drawings Form: SESV1621

Date: 8/92

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© 1992 Caterpillar Inc.

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• Controller located outside the cab

• Totally sealed unit

• 3 LED's (arrow) for some diagnostics

2

Component Location and Function

The controller is located in an outside compartment above and behind the battery box. A panel must be removed to access the controller. The controller is a totally sealed unit like the transmission controls for Caterpillar Off-highway Trucks and Wheel Tractor-Scrapers. The only time when removal of the compartment cover will be necessary is when the monitor panel on the operator's console in the cab shows the controller fault symbol or when the diagnostic error codes indicate that the three diagnostic Light Emitting Diodes (LED's - arrow) need to be checked. The fault symbols and error codes will be discussed in detail later in this presentation.

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•If controller fault symbol stays ON, check the LED's

• Yellow LED ON, communication problem with monitor

• Red LED ON steady or flashing, replace CPU

• Green LED ON, normal operation

3

As mentioned in the previous slide, if the controller fault symbol on the monitor panel comes ON and stays ON, a problem in the controller system is indicated. The three diagnostic LED's on the controller will provide an indication of the problem.

When the yellow LED turns ON, a communication problem with the monitor is indicated.

If the red LED is ON (steady or flashing), the Central Processor Unit (CPU) is not functioning correctly and must be replaced.

During engine start-up, the three LED's will briefly illuminate. The red and yellow LED's will quickly turn OFF leaving just the green LED ON, which indicates normal operation.

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• Monitor panel: - Push buttons

activate many functions

- Displays information

• Engine speed dial: - Ten positions

- Replaces governor control lever

4

The operator's console has a monitor panel that permits several machine functions to be activated with push buttons. The monitor panel also displays information about the machine operating status and diagnostic information.

The machine is equipped with an engine speed dial that has ten different positions. This digital rotary switch replaces the governor control lever which was used in earlier hydraulic excavators. The engine speed dial will also be discussed in detail later in this presentation.

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• Two backup systems: - Engine speed dial

(two switches) - Pump control (one

switch)

• Speed dial rear switch: - Normally run in

"AUT" position - Dial disconnected in

"MAN" position

• Speed dial front switch:

- "Rabbit" position increases rpm - "Tortoise" position

decreases rpm

• Pump control switch: - Normally run in

5

Two backup systems are provided to prevent machine down situations. One backup system is for the engine speed dial and the second is for the pump controls. Each system is activated by toggle switches at the rear of the operator's seat arm consoles.

The engine speed dial circuit (shown) has two backup switches on the right console. The rear switch is normally run in the "AUT" position. When the switch is moved to the "MAN" position, the engine speed dial signal is disconnected from the controller. The front switch is then used to manually control the engine speed. Push the front switch toward the "Rabbit" to increase engine speed or toward the "Tortoise" to decrease engine speed.

The pump control backup switch (not visible in this view) is the single toggle switch on the left console. The backup switch has two positions--"AUT" and "Tortoise." This switch also is normally run in the positions--"AUT" position. If a pump control problem occurs, move the switch to the "Tortoise" position. The pump control is bypassed and power to the

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• Monitor panel: - Upper section has

readout devices - Lower section has

push buttons - LED's tell when

function is ON or OFF

• Four red LED's make up warning system master lamp

• Three digit display: - Operating parameters - Error codes - Used in diagnostics • LCD gauges: - Engine temperature - Fuel level - Hydraulic oil temperature 6

The monitor panel, located in front and to the right of the operator's seat, has two sections. The upper section contains readout devices and the lower section contains push button switches which control many machine functions. The push buttons are labeled and have LED's which indicate when the function is ON or OFF.

At the top of the upper section are four red LED's. These LED's make up the master lamp, which is part of the warning system. The warning system is activated when various machine system faults are detected by the controller. In the top right corner of the upper section is a three digit Liquid Crystal Display (LCD) which indicates various machine operating parameters and, during diagnostic procedures, displays information on machine systems, components, and error codes. Below this display are three rotary LCD's which indicate engine coolant temperature, fuel quantity and hydraulic oil temperature.

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• Seven LED fault symbols

7

Across the bottom of the upper section (below the rotary displays) are seven LED fault symbols that illuminate when an out of tolerance condition occurs. These symbols (from left to right) are:

- Air intake heater (for 320 Excavator with 3066 engine)

- Charging system

- Engine coolant temperature

- Hydraulic oil temperature

- Engine oil pressure

- Controller system

- Monitor system

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• Ether aid switch

• Start switch

• Engine speed dial:

- Ten positions - Each position has a

specific no load speed

8

This view shows the ether aid switch, start switch and the engine speed dial with the "tortoise" and "rabbit" symbols and an ascending pictorial scale. As previously stated, the engine speed dial has ten positions.

The monitor panel indicates the engine speed dial position from 1 through 10. Each dial position has a specific no load engine speed.

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9 • ECU sends PWM signals to: - PRV - Hydraulic oil temperature sensor - Governor actuator motor • PWM signals: - Specific voltage level

- "Pulsed" on and off - ON time controlled

by ECU

- Cannot be measured

PULSE WIDTH MODULATED (PWM) SIGNALS

ONE

CYCLE

VOLTAGE

ON

VOLTAGE

LEVEL

MEAN VOLTAGE

VOLTAGE

OFF

Pulse Width Modulated Signals

The 320/330 uses a Pulse Width Modulated (PWM) signal from the controller to the Proportional Reducing Valve (PRV) which is identical to the signal used on the "E" series hydraulic excavators. In addition, the hydraulic oil temperature sensor and governor actuator motor on the 320/330 receive PWM signals.

A PWM signal is a specific voltage level (for example, from 0 to 24 volts) that is "pulsed" (turned ON and OFF repeatedly). This voltage level is represented by the height of the vertical step in the slide. The time of the "pulse" (or ON time) will be varied by the controller. The time is

represented by the horizontal length of the "pulse" in the slide. This time is normally a percentage of the total ON time available for the "pulse."

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10

• Now a sealed unit, located outside the cab

CONTROLLER CHANGES. . .

• Three diagnostic LED's in the cover

• It operates the electronic governor control

• Functions as an underspeed controller,

but ONLY in Power Mode llI, and if the

engine speed dial is at position “10”

• Has an “anti-stall” feature instead of the

“self-learning” function

• Has more “inputs” and “outputs”

Controller Changes

This slide summarizes some of the changes which have been made to the 320/330 controller from the "E" series hydraulic excavators.

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• The controller has continual interactive

communication with the monitor panel

• Controls the work mode solenoids, the two-speed

travel solenoid and relays for the lights, wiper and

washer solenoids

• Stores fault codes for later retrieval

• Provides three levels of Automatic Engine Control,

or AEC

• Has two built-in diagnostic service modes

- Data mode and Calibration mode

CONTROLLER CHANGES. . .

• Has two backup systems, one for the pump

control and another for the engine speed dial

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• Communicates with the controller

• Has LCD displays in place of gauges

• Has push buttons that control many machine

functions and access diagnostic procedures

• Has a three digit character readout that...

- shows engine speed dial position

- displays fault codes for controller/monitor

problems

- indicates when either or both backup

systems are activated

THE MONITOR. . .

Monitor Features

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13 FAULT ALARM ENG. OIL PRESS. SWITCH MONITOR SWING PRIORITY SOLEN. VALVE ENG. SPEED DIAL TRAV. PRESS. SWITCH BM. UP PRESS. SWITCH IMPL. /SW. PRESS. SWITCH FUEL LEVEL SENSOR HYD. OIL TEMP. SENSOR ENG. COOLANT TEMP. SENSOR TRAV. SPD. SOLEN. VALVE FINE CONTROL SOLEN. VALVE LOW IDLE SWITCH TRAVEL ALARM PRV P/S PRESSURE BACKUP SWITCH SPEED CHANGE SWITCH SPD. DIAL BACKUP SW. ENGINE PUMP G/A FUSE BOX START SWITCH G/A FDBK SENSOR

INPUTS TO CONTROLLER

RELAY BOX SPEED SENSOR CHASSIS LIGHT BOOM

LIGHT WIPER WASHER

BATTERY ALT. ECU (CONTROLLER) ATTACH. PRESS. SWITCH

Controller Input Components

On this diagram, all of the inputs to the controller have been color coded red.

Fuse box: Electrical power from the battery and start switch is sent

through the fuse box to the controller.

Monitor: Sends a number of input signals to the controller which will be

explained in detail later in this presentation.

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Engine speed dial: A rotary switch which is located on the operator’s

console in the cab.

Travel pressure switch: Tells the controller when a travel circuit is

activated and is mounted on the top front of the main implement control valve.

Implement/swing pressure switch: Tells the controller when an

implement or the swing circuit is activated; also mounted on the top front of the main control valve.

Boom up pressure switch: Tells the controller when the boom control is

fully stroked for "boom up."

Engine coolant temperature sensor: Located on the water pump

housing.

Hydraulic oil temperature sensor: Located on the right rear lower

corner of the hydraulic tank.

Fuel level sensor: Located on the right rear lower corner of the fuel tank

and is visible from the pump compartment.

Alternator: Sends a signal to the controller indicating correct operation. Engine oil pressure switch: Located in the rear by the engine oil gallery. One-touch low idle switch: Part of the automatic engine speed control

system; located on top of the right joystick.

Attachment pressure switch: Sends a signal to the controller when an

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14 FAULT ALARM ENG. OIL PRESS. SWITCH MONITOR SWING PRIORITY SOLEN. VALVE ENG. SPEED DIAL TRAV. PRESS. SWITCH BM. UP PRESS. SWITCH IMPL. /SW. PRESS. SWITCH FUEL LEVEL SENSOR HYD. OIL TEMP. SENSOR ENG. COOLANT TEMP. SENSOR TRAV. SPD. SOLEN. VALVE FINE CONTROL SOLEN. VALVE LOW IDLE SWITCH TRAVEL ALARM PRV P/S PRESSURE BACKUP SWITCH SPEED CHANGE SWITCH SPD. DIAL BACKUP SW. ENGINE PUMP G/A FUSE BOX START SWITCH RELAY BOX SPEED SENSOR CHASSIS LIGHT BOOM LIGHT WIPER WASHER BATTERY ALT. ECU (CONTROLLER) G/A FDBK SENSOR ATTACH. PRESS. SWITCH

Controller Output Components

Shown here is the same diagram but with all the controller outputs color coded red.

Monitor: In addition to serving as an input component, the monitor also

receives signals from the controller.

Governor actuator motor: Electrically controls engine rpm as indicated

by speed dial settings.

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Swing priority (Crowding) solenoid valve: Also activated by the

controller after a signal is received from the WORK push button switch on the monitor panel.

Two speed travel solenoid valve: Activated by the controller after a

signal is received from the TRAVEL SPEED push button switch on the monitor panel.

Fault alarm: An audible horn or buzzer.

Travel alarm: Activated by the controller after a signal is received from

the travel pressure switch.

Windshield wiper relay: Actuated by the controller after a signal is

received from the WIPER push button switch on the monitor panel.

Windshield washer relay: Actuated by the controller after a signal is

received from the WASHER push button switch.

Chassis light relay: Actuated by the controller after a signal is received

from the LIGHT push button switch.

Boom light relay: Also actuated after a signal is received from the

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• Power mode selector switch sends signal to controller

• LED's indicate levels I, II, or III

• Power modes match machine power to task • Available engine

PERFORMANCE

MONITOR

1 2 1 2 POWER III II I WORK

TRAVEL SPEED ALARM CANCEL

LIGHT WIPER WASHER ON

AEC

POWER MODE

SELECTION

Power Mode Selection

The power mode selector switch, located on the monitor panel, signals the controller which power mode level has been chosen. Three symbols with corresponding LED's indicate which level (I, II or III) has been selected. Each time the switch is pushed, the power mode will cycle to a different level and illuminate an LED.

The three power modes permit the operator to match the machine power to the task by providing a different amount of hydraulic horsepower for the implement, swing and travel systems. The amount of available engine horsepower that can be utilized in each of the three power modes is:

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• Pump pressure plotted against flow

• Both pumps equally loaded • Implement/swing pressure switch closed • Travel pressure switch open

• Top curve for Power Mode III

•Middle curve for Power Mode II 10 20 30 40 50 60

PUMP PRESSURE (PSI)

1000 2000 3000 4000 5000 46 GPM 2130 PSI 37 GPM 1480 PSI 22 GPM 2490 PSI 20 GPM 15 GPM 9 GPM A B 40 GPM 1990 PSI C 27 GPM 2775 PSI 25 GPM 3980 PSI PUMP FLOW (GPM) IMPL. R/V SETTING 4550 PSI 0 0 DIAL "7~10" DIAL "9~10" DIAL "10" III II I

320 P-Q CHARACTERISTICS

3116 ENGINE WITH BENT AXIS PUMP

2 PUMPS EQUALLY LOADED WITH IMPLEMENTS ONLY

NOTE

VALUES SHOWN ARE EXAMPLES ONLY THEY SHOULD NOT BE USED

FOR PUMP TESTS

POWER SHIFT PRESSURE

POINT A = approx 255 ps POINT B = approx 290 psi POINT C = approx 320 psi

P-Q Curves (320 with 3116 engine and Bent Axis Pump)

The three curves on this diagram show pump pressure plotted against pump flow for each of the three power modes when only an implement or swing circuit is loaded. Each curve shows the flow for one pump when both pumps are equally loaded. The controller detects when only an implement or swing circuit is loaded because the implement/swing pressure switch at the main control valve is closed and the travel pressure switch at the main control valve is open (no pressure in the travel

circuits).

The top curve, for Power Mode III, shows that the pump begins to destroke at Point A, which is approximately 14700 kPa (2130 psi). At that time, the power shift pressure is approximately 1750 kPa (255 psi). The middle curve, for Power Mode II, shows that the pump begins to destroke at Point B, which is approximately 13700 kPa (1990 psi). At that time, the power shift pressure is approximately 2000 kPa (290 psi).

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Power Mode I

The bottom curve, for Power Mode I, shows that the pump begins to destroke at Point C, which is approximately 10200 kPa (1480 psi). At that time, the power shift pressure is approximately 2200 kPa (320 psi).

NOTE TO THE INSTRUCTOR: All values shown are for CLASSROOM REFERENCE ONLY and should not be used for diagnostic purposes.

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• Middle curve for Power Mode II 10 20 30 40 50 60

1000 2000 3000 4000 5000 48 GPM 1900 PSI 40 GPM 1450 PSI 21 GPM 2550PSI 16 GPM 14 GPM 9 GPM A B 43 GPM 1500 PSI C 23 GPM 3050 PSI 29 GPM 3050 PSI

PUMP FLOW (GPM) _{POWER SHIFT PRESSURE}

POINT A = approx 230 psi POINT B = approx 280 psi POINT C = approx 310 psi

IMPL. R/V SETTING 4550 PSI 0 0 DIAL "7~10" DIAL "9~10" DIAL "10" III II I

320 P-Q CHARACTERISTICS

3066 ENGINE WITH SWASHPLATE PUMP

2 PUMPS EQUALLY LOADED WITH IMPLEMENTS ONLY

NOTE

FOR PUMP TESTS

P-Q Curves (320 with 3066 engine and Swashplate Pump)

circuits).

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Power Mode I

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18

• Middle curve for Power Mode II 10 20 30 40 50 60

1000 2000 3000 4000 5000 59 GPM 3130 PSI 47 GPM 2200PSI 34 GPM 3050 PSI 38 GPM 28 GPM 20GPM A B 57 GPM 2485 PSI C 39 GPM 3335 PSI 42 GPM 4130 PSI

PUMP FLOW (GPM) POWER SHIFT PRESSURE

POINT A = approx 160 psi POINT B = approx 185 psi POINT C = approx 200 psi

IMPL. R/V SETTING 4550 PSI 0 0 DIAL "7~10" DIAL "9~10" DIAL "10" III II I

330 P-Q CHARACTERISTICS

2 PUMPS EQUALLY LOADED

WITH IMPLEMENTS ONLY

NOTE

FOR PUMP TESTS

P-Q Curves (330 with 3306 engine)

circuits).

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Power Mode I

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• Only one pump loaded

• Power Mode III with speed dial at 10 • Only implement loaded: - Implement/swing pressure switch closed - Travel pressure switch open 1000 2000 3000 4000 5000 POWER SHIFT PRESSURE Pt. A = 130 psi Pt. B = 45 psi 10 20 30 40 50 60

PUMP FlOW (GPM) A B 31 GPM 23 GPM 49 GPM 2490 PSI 47 GPM 3980 PSI 27 GPM 3980 PSI IMPLEMENTS TRAVEL 4550 PSI IMPL. R/V SETTING 5000 PSI TRAVEL R/V SETTING 0 0 NOTE

FOR PUMP TESTS

320 PUMP P-Q CHARACTERISTICS

3116 ENGINE WITH BENT AXIS PUMP

ONE PUMP LOADED WITH IMPLEMENTS OR TRAVEL IN POWER MODE III

P-Q Curves (320 with 3116 engine and Bent Axis Pump)

These two curves show the pump pressure plotted against flow when only one pump is loaded for either an implement/swing circuit or for the travel circuit. The values shown here are for Power Mode III with the engine speed dial at position 10.

Again, the controller can detect when only an implement is loaded

because the implement/swing pressure switch at the main control valve is closed and the travel pressure switch at the main control valve is open (no pressure in the travel circuits). The pump begins to destroke at Point A, which is approximately 17100 kPa (2490 psi). Power shift pressure will be approximately 900 kPa (130 psi) at that time.

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- Travel pressure switch closed - Implement/swing pressure switch open • Constant signal to PRV as circuit is loaded • Engine rpm decreases to target speed • Signal to PRV varies to maintain target speed

The controller can detect when only the travel circuit is loaded because the travel pressure switch at the main control valve is closed and the implement/swing pressure switch at the main control valve is open (no pressure in the implement/swing circuits). When using one pump to load a travel circuit (as in a pivot turn), the pump begins to destroke at Point B, which is approximately 27400 kPa (3980 psi). Power shift pressure will be approximately 300 kPa (45 psi) at that time.

Thus, the controller sends a constant level of electrical signal to the PRV when loading the implement/swing or travel circuit. After the engine speed decreases to the target speed of approximately 1750 rpm, the controller varies the electrical signal to the PRV to maintain that target speed.

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• Power Mode III with speed dial at 10 • Only implement loaded: - Implement/swing pressure switch closed - Travel pressure switch open 1000 2000 3000 4000 5000 POWER SHIFT PRESSURE Pt. A = 185 psi Pt. B = 28 psi 10 20 30 40 50 60

PUMP FlOW (GPM) A B 27 GPM 17 GPM 43 GPM 2670 PSI 42 GPM 3980 PSI 20 GPM 3980 PSI IMPLEMENTS TRAVEL 4550 PSI IMPL. R/V SETTING 5000 PSI TRAVEL R/V SETTING 0 0 NOTE

FOR PUMP TESTS

320 PUMP P-Q CHARACTERISTICS

3066 ENGINE WITH SWASHPLATE PUMP

P-Q Curves (320 with 3066 engine and Swashplate Pump)

These two curves show the pump pressure plotted against flow when only one pump is loaded for either an implement/swing circuit or for the travel circuit. The values shown here are for Power Mode III with the engine speed dial at position 10.

Again, the controller can detect when only an implement is loaded

because the implement/swing pressure switch at the main control valve is closed and the travel pressure switch at the main control valve is open (no pressure in the travel circuits). The pump begins to destroke at Point A, which is approximately 18400 kPa (2670 psi). Power shift pressure will be approximately 1275 kPa (185 psi) at that time.

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- Travel pressure switch closed - Implement/swing pressure switch open • Constant signal to PRV as circuit is loaded • Engine rpm decreases to target speed • Signal to PRV varies to maintain target speed

The controller can detect when only the travel circuit is loaded because the travel pressure switch at the main control valve is closed and the implement/swing pressure switch at the main control valve is open (no pressure in the implement/swing circuits). When using one pump to load a travel circuit (as in a pivot turn), the pump begins to destroke at Point B, which is approximately 27400 kPa (3980 psi). Power shift pressure will be approximately 200 kPa (28 psi) at that time.

As in the preceding example, the controller sends a constant level of electrical signal to the PRV when loading the implement/swing or travel circuit. After the engine speed decreases to the target speed of

approximately 1750 rpm, the controller varies the electrical signal to the PRV to maintain that target speed.

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• Power Mode III with speed dial at 10 • Only implement loaded: - Implement/swing pressure switch closed - Travel pressure switch open Pt. A=100 psi POWER SHIFT PRESSURE 1000 2000 3000 4000 5000 10 20 30 40 50 1000 60

PUMP FlOW (GPM) A 53 GPM 61 GPM 4195 PSI IMPLEMENTS 4550 PSI IMPL. R/V SETTING 5000 PSI TRAVEL R/V SETTING 0 0 NOTE

FOR PUMP TESTS

34 GPM

330 PUMP P-Q CHARACTERISTICS

P-Q Curve (330 with 3306 engine)

This curve shows the pump pressure plotted against flow when only one pump is loaded for either an implement/swing circuit or for the travel circuit. The values shown here are for Power Mode III with the engine speed dial at position 10.

The controller can detect when only an implement is loaded because the implement/swing pressure switch at the main control valve is closed and the travel pressure switch at the main control valve is open (no pressure in the travel circuits). The pump begins to destroke at Point A, which is approximately 28920 kPa (4195 psi). Power shift pressure will be approximately 685 kPa (100 psi) at that time.

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PRV as circuit is loaded • Engine rpm decreases to target speed • Signal to PRV varies to maintain target speed

The controller sends a constant level of electrical signal to the PRV when loading the implement/swing or travel circuit. After the engine speed decreases to the target speed of approximately 1750 rpm, the controller varies the electrical signal to the PRV to maintain that target speed.

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• Pump flow regulated by controller • Controller sends electrical signal to PRV • PRV sends pressure signal to pumps • Pressure signal affects both pumps

PUMP

REGULATOR

PROPORTIONAL REDUCING VALVE ENGINE SPEED SENSOR

PUMP CONTROLS

POWER MODE SELECTION

PILOT PUMP RESOLVER VALVE MONITOR ENGINE SPEED DIAL TRAV. PRESS. SWITCH IMP. SW. PRESS. SWITCH PUMP ECU P/S PRESS FROM PRV P/S PRESSURE FROM PRV ATTACH. PRESS. SWITCH (IF EQUIPPED) Pump Regulation

Pump flow is regulated by the controller. As machine operation begins, the implement/swing pressure switch or the travel pressure switch closes because pressure in the main control valve logic circuit increases. The controller then processes the signals from the power mode switch, engine speed dial and the engine speed sensor to determine the level of electrical signal that is sent to the proportional reducing valve. The PRV then sends a variable reduced pilot system pressure signal (called power shift

pressure) to the hydraulic pump regulators. Power shift pressure affects both pumps at the same time based on the power mode level selected by the operator.

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• Signal from controller to PRV is constant and high

• Pumps destroke at low system pressure

• Both pump flows vary with pump pressures

• Signal from controller to PRV is constant but less than Power Mode I

• Pumps destroke at slightly higher system pressure

• Power shift pressure remains constant

• Signal from controller is constant but less than Power Mode II

• Pumps destroke at higher pressure than Power Mode II

• Power shift pressure remains constant • Controller functions as underspeed control • As engine speed decreases, controller signal increases • Controller varies signal to maintain engine rpm near full

In Power Mode I, the electrical signal from the controller to the PRV is constant and high. The PRV sends a constant and high power shift

pressure to the pumps causing them to begin destroking at a relatively low pump system pressure. As system pressure in each pump increases above 10700 kPa (1550 psi), the power shift pressure does not change. The increased pump pressures, acting internally in the pump regulators, begin to destroke the pumps. Both pump flows will increase or decrease as pump pressures decrease or increase.

Power Mode II: Any engine speed dial position

In Power Mode II, the electrical signal from the controller to the PRV is still constant but slightly lower than in Power Mode I, so the power shift pressure to the pumps is also slightly lower. The pumps begin to destroke at a slightly higher pump system pressure than in Power Mode I. As pump pressure increases and flow decreases, the power shift pressure will remain relatively constant. Again, pump flow is regulated by the

individual pump system pressure acting internally in the pump regulators (as described in Power Mode I).

Power Mode III: Engine speed dial positions 1 through 9

In Power Mode III, the electrical signal from the controller to the PRV is still constant but slightly lower than in Power Mode II, so the power shift pressure to the pumps is also slightly lower. The pumps begin to destroke at a slightly higher pump system pressure than in Power Mode II. As stated previously, when pump pressure increases and flow decreases, the power shift pressure will remain relatively constant. Pump flow is still regulated by the individual pump system pressure acting internally in the pump regulators (as described in Power Modes I and II).

Power Mode III: Engine speed dial position 10

If the engine speed dial is at 10 and the pumps are loaded, the controller functions as an underspeed control. The controller monitors engine speed from the speed sensor and, as engine speed decreases to near full load (1980 rpm for 320, 1950 rpm for 330), the controller begins to increase the electrical signal to the PRV. The PRV increases the power shift signal to the pumps and the pumps begin to destroke. The controller continually varies the electrical signal to the PRV to maintain engine speed as near to full load rpm as possible.

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• Power Mode I: Engine rpm limited to speed dial position 7

• Power Mode II: Engine rpm limited to speed dial position 9

• Power Mode III: Engine rpm limited to speed dial position 10

III II I 1 2 1 2 GOVERNOR ACTUATOR ENGINE SPEED DIAL PUMP SPEED SENSOR PROPORTIONAL REDUCING VALVE ENGINE

ELECTRONIC

CONTROL CIRCUITS

SPEED DIAL LIMITS

POWER MODE SWITCH MONITOR

ECU

FEEDBACK SENSOR (CONTROLLER)

POWER

lll

l

ll

Speed Dial Limits

The engine speed is limited by the power mode setting chosen. When Power Mode I is selected, the maximum engine rpm is limited to that of the engine speed dial at position 7, even if the dial is at position 8, 9 or 10. If the dial is at position 6 or below, the maximum engine rpm will be that of the selected dial position.

In Power Mode II, the maximum engine rpm is limited to that of dial position 9, even if the dial is at position 10. If the dial is at position 8 or below, the maximum engine rpm will be that of the selected dial position.

In Power Mode III, the maximum engine rpm is limited to that of the engine speed dial at position 10. If the dial is at position 9 or below, the maximum engine rpm will be that of the selected dial position.

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SYSTEMS OPERATION

The 320/330 controllers provide a number of operational benefits. Productivity is a function of all systems operating correctly and within design specifications. A thorough understanding of how the controller can vary the machine operational parameters will enhance productivity and the ability to isolate performance related problems.

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25

• Normal operation in Power Mode III

• Engine speed dial at position 10

• Controls in HOLD, three seconds before AEC comes ON

• Engine rpm to be lowered

• Controls in HOLD for three seconds, AEC is OFF

• Pumps at low standby flow POWER SHIFT PRESSURE

275 psi

190 psi

260 psi

185 psi

255psi

1970

1790

1750

ENGINE RPM

1300

1870

940 1850

High Idle

(3 sec. period before AEC comes ON)

Both pumps pressurized up to main relief pressure

Boom Up and Swing AEC ON

THE VALUES SHOWN ARE FOR THE 320, 320L. ACTUAL VALUES WILL VARY WITH MACHINE MODEL

AEC Level l

One-Touch Low Idle ON

320 SYSTEM BEHAVIOR

NORMAL OPERATION

320 System Behavior

Engine speed and power shift pressures will vary during different operating conditions. This chart provides examples of approximate engine rpm and power shift pressure during different machine operating conditions. For all conditions, the machine is shown during normal operation in Power Mode III with the engine speed dial at position 10.

High Idle: All controls are in NEUTRAL or HOLD during the three

seconds before the Automatic Engine Control (AEC) comes ON. Engine speed is 1970 rpm and power shift pressure is approximately 1910 kPa (275 psi). Engine speed is about to be reduced to AEC level 1 or 2.

No Load, Maximum RPM: All controls are in NEUTRAL or HOLD for

three seconds and the AEC switch is OFF. Engine speed is 1870 rpm and power shift pressure is approximately 1910 kPa (275 psi). The hydraulic pumps are at low standby flow and pump pressures are below 3450 kPa (500 psi). Component wear will be reduced and fuel consumption is low.

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• Pump pressures at relief valve setting

• Controller monitoring engine speed

• Boom up and swing at same time

• Controls in HOLD for three seconds, AEC is ON

• Pumps at low standby flow

• One-touch low idle switch is ON

Normal Load, Below Full Load Speed: Both pumps are pressurized up

to the implement relief valve setting. Engine speed is approximately 1790 rpm and power shift pressure is from 1325 to 1815 kPa

(190 to 260 psi). Pump pressures are at 31350 kPa (4550 psi) and pump flows are approximately 76 l/min. (20 gpm). The controller is monitoring engine speed to either increase or decrease the electrical signal to the PRV.

Maximum Flow, Full Load Speed: Booming up and swinging at the

same time. Engine speed is approximately 1800 rpm and power shift pressure is from 1275 to 1765 kPa (185 to 255 psi). Pump pressures are at 24100 kPa (3500 psi) and pump flows are approximately 129 l/min. (34 gpm).

AEC On: All controls are in NEUTRAL or HOLD for three seconds and

the AEC switch is ON. Engine speed is approximately 1300 rpm and power shift pressure is approximately 1910 kPa (275 psi). Hydraulic pressures are below 3450 kPa (500 psi) and the pumps are at low standby flow of approximately 34 l/min. (9 gpm).

One-Touch Low Idle: One-touch low idle switch is ON. Engine speed

is approximately 950 rpm and power shift pressure is approximately 2050 kPa (295 psi). Hydraulic pump pressures are below 3450 kPa (500 psi) and the pumps are at low standby flow of approximately 34 l/min. (9 gpm).

NOTE TO THE INSTRUCTOR: Power shift pressures shown are for example only and should not be used for testing and adjusting.

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26

• Normal operation in Power Mode III

• Engine speed dial at position 10

• Controls in HOLD, three seconds before AEC comes ON

• Engine rpm to be lowered

• Controls in HOLD for three seconds, AEC is OFF

• Pumps at low standby flow POWER SHIFT PRESSURE

205 psi

140 psi

170 psi

115 psi

185 psi

1960

1790

ENGINE RPM

1300

1860

850 1840

High Idle

(3 sec. period before AEC comes ON)

Both pumps pressurized up to main relief pressure

Boom Up and Swing AEC ON

THE VALUES SHOWN ARE FOR THE 330, 330L. ACTUAL VALUES WILL VARY WITH MACHINE MODEL

AEC Level I

One-Touch Low Idle ON

330 SYSTEM BEHAVIOR

330 System Behavior

Engine speed and power shift pressures will vary during different operating conditions. This chart provides examples of approximate engine rpm and power shift pressure during different machine operating conditions. For all conditions, the machine is shown during normal operation in Power Mode III with the engine speed dial at position 10.

High Idle: All controls are in NEUTRAL or HOLD during the three

seconds before the Automatic Engine Control (AEC) comes ON. Engine speed is 1960 rpm and power shift pressure is approximately 1420 kPa (205 psi). Engine speed is about to be reduced to AEC level 1 or 2.

No Load, Maximum RPM: All controls are in NEUTRAL or HOLD for

three seconds and the AEC switch is OFF. Engine speed is 1870 rpm and power shift pressure is approximately1420 kPa (205 psi). The hydraulic pumps are at low standby flow and pump pressures are below 3450 kPa (500 psi). Component wear will be reduced and fuel consumption is low.

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relief valve setting

• Controller monitoring engine speed

• Boom up and swing at same time

• Controls in HOLD for three seconds, AEC is ON

• One-touch low idle switch is ON

Normal Load, Below Full Load Speed: Both pumps are pressurized up

to the implement relief valve setting. Engine speed is approximately 1790 rpm and power shift pressure is from 980 to 1175 kPa

(140 to 170 psi). Pump pressures are at 31350 kPa (4550 psi) and pump flows are approximately 145 l/min. (38 gpm). The controller is

monitoring engine speed to either increase or decrease the electrical signal to the PRV.

Maximum Flow, Full Load Speed: Booming up and swinging at the

same time. Engine speed is approximately 1790 rpm and power shift pressure is from 785 to 1275 kPa (115 to 185 psi). Pump pressures are at 24100 kPa (3500 psi) and pump flows are approximately 190 l/min. (50 gpm).

AEC On: All controls are in NEUTRAL or HOLD for three seconds and

the AEC switch is ON. Engine speed is approximately 1300 rpm and power shift pressure is approximately 1420 kPa (205 psi). Hydraulic pressures are below 3450 kPa (500 psi) and the pumps are at low standby flow of approximately 34 l/min. (9 gpm).

One-Touch Low Idle: One-touch low idle switch is ON. Engine speed

is approximately 850 rpm and power shift pressure is approximately 1420 kPa (205 psi). Hydraulic pump pressures are below 3450 kPa (500 psi) and the pumps are at low standby flow of approximately 34 l/min. (9 gpm).

NOTE TO THE INSTRUCTOR: Power shift pressures shown are for example only and should not be used for testing and adjusting.

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27

• Hydraulic torque for each speed dial position

• Power Mode III, dial position 10 • Engine rpm decreases to target speed • Controller varies signal to maintain target rpm

6

7

8

9

5

4

3

1

10

LOW IDLE

2

HIGH IDLE

ENGINE SPEED DIAL POSITION

HYDRAULIC TORQUE l RATED = 1800 RPM TARGET SPEED = 1790 RPM (330) 1750 RPM (320) HYDRAULIC TORQUE ll lll

320-330 POWER MODE SETTINGS

Power Mode Settings

This chart shows hydraulic torque in each of the three power modes for each of the ten engine speed dial positions. The normal engine torque curve (black) is at the top.

The Power Mode III torque curve (red) is the second curve from the top. When the engine speed dial is in position 10 and the machine begins working, the engine speed will decrease from high idle rpm toward the full load speed of 1800 rpm. The full load speed is near the target speed

(1750 rpm for 320, 1790 rpm for 330) for Power Mode III and dial position 10. After the engine rpm decreases to the target speed, the controller varies the electrical signal to the PRV to maintain the engine rpm at or near the target speed.

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position 9 or below

• Engine rpm decreases, pumps destroke

• Steady signal to PRV

• Power Modes I and II are similar

• Engine rpm decreases, pumps destroke

• Steady signal to PRV

• Pump flow controlled by system pressures

When the engine speed dial is in position 9 or below (but still in Power Mode III) and the machine begins working, the engine rpm will decrease from the no load speed for that dial position until the pump system pressure begins to destroke the pump. In this condition, the controller sends a steady signal to the PRV and pump flow is controlled only by the pump system pressures.

The Power Mode II curve (blue) and Power Mode I curve (yellow) show similar characteristics. Power Mode II engine speed begins at dial position 9 and the controller sends a steady and slightly higher electrical signal to the PRV than in Power Mode III and dial position 9. Power Mode I begins at dial position 7 and the controller sends a steady and slightly higher electrical signal to the PRV than in Power Mode II. As the machine begins working, the engine speed will decrease from the no load speed for a selected dial position until pump pressure begins to destroke the pumps. Remember, the controller sends a steady signal to the PRV during these conditions and pump flow is controlled only by pump system pressures.

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28

• Anti-stall function

• Engine 250 rpm below no load speed for selected dial position

• Signal to PRV increases

• Flow rates decrease to unload engine 6 8 5 3 1 2 4 10 HYD TORQUE

LOW IDLE 7 9 HIGH IDLE

l

ll lll

CONSTANT TORQUE CONTROL LINE

ENGINE SPEED DIAL POSITION ANTI-STALL

CONTROL LINE

320-330 POWER MODE SETTINGS

ANTI-STALL FUNCTION

The anti-stall function of the 320/330 controller replaces the self-learning function which was used on the "E" series excavator controllers.

When the machine is operating in Power Mode I and II or in Power Mode III with the engine speed dial in position 9 or below, the power shift pressure is constant. (Remember, however, that the power shift pressures are different for each of these conditions.) The controller monitors engine speed and, if the engine speed decreases 250 rpm below the no load speed of the engine speed dial, the controller begins to increase the electrical signal to the PRV. The PRV then increases the power shift pressure sent to the pumps and causes the pump flow rates to decrease, thereby

unloading the engine. When the engine speed increases above the engine speed dial less 250 rpm value, the controller again provides a constant electrical signal to the PRV.

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position 8 • Engine rpm decreases to 1500 • Signal to PRV increases, pumps destroke

In the example shown on the graph, a 320 excavator is operating in Power Mode II with the engine speed dial in position 8. The no load engine speed is 1750 rpm. As the machine begins to operate, the engine speed decreases to 1500 rpm. To this point, the controller was supplying a constant electrical signal to the PRV. After the engine speed decreases to 1500 rpm, however, the controller begins to increase the signal to the PRV causing the pumps to destroke and unload the engine. When engine speed increases above 1500 rpm, the controller again supplies a constant

electrical signal to the PRV.

NOTE: The anti-stall feature functions as described above for each of the engine speed dial positions and power mode levels except Power Mode III and dial position 10.

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29

• Power mode setting vs hydraulic horsepower

• Power reduction curves for all three modes ENGINE RPM 800 1000 1200 1400 1600 1800 2000 HYDRAULIC HORSEPOWER l ll lll RATED SPEED POWER MODE VS. HYDRAULIC HORSEPOWER 1 2 3 4 5 6 7 8 9 10 ENGINE HORSEPOWER SPEED DIAL SETTINGS

This graph compares available engine horsepower to the hydraulic

horsepower for each engine speed dial position in each power mode. The top curve (black) represents the available engine horsepower. Power Mode III is shown by the red curve, Power Mode II by the blue curve and Power Mode I by the yellow curve.

This graph illustrates the reduction in power capabilities for all three power modes. Notice how the power decreases from approximately 100% in Power Mode III, to 85% in Power Mode II, to 65% in Power Mode I.

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30 • Purpose of AEC: - Reduce fuel consumption - Reduce noise - Decrease rpm when demand is low GOVERNOR ACTUATOR ENGINE SPEED SENSOR

AUTOMATIC ENGINE

SPEED CONTROL CIRCUIT

(AEC)

MONITOR TRAVEL PRESSURE SWITCH IMPLEMENT/SWING PRESSURE SWITCH III II I 1 2 1 2 AEC SWITCH

ECU

ON

Automatic Engine Control (AEC)

The purpose of the automatic engine speed control that is used on the "E" series excavators and 200 family of excavators is to reduce fuel

consumption and engine/machine noise by automatically reducing engine speed when no hydraulic power is demanded. The 320/330 AEC has these same features, but also slightly decreases engine rpm when the hydraulic power demand is very low. This rpm decrease occurs regardless of the power mode that has been selected. The three levels of AEC on the 320/330 are defined as:

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• Three levels of AEC _{1. No load: No hydraulic demand (control levers in NEUTRAL or}

HOLD) for 3 seconds.

2. Light load: Engine speed is 50 rpm or less below the no load setting

for 10 or more seconds while an implement or travel circuit is in operation.

3. Normal load: Engine speed is 70 rpm or more below the no load

setting while an implement or travel circuit is in operation.

NOTE: Specific engine speed settings for each condition are provided in the Serviceman's Handouts in the back of this presentation.

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31

• Switch operates only with no demand

• First depression decreases rpm

• Second depression increases rpm

• Applied load at low rpm causes increase to no load setting

ECU

ONE-TOUCH

LOW IDLE CONTROL CIRCUIT

IDLE SWITCH ENGINE SPEED DIAL TRAVEL PRESSURE SWITCH IMPLEMENT/SWING PRESSURE SWITCH ENGINE SPEED SENSOR GOVERNOR ACTUATOR

One-touch Low Idle Control

The final speed variable in the system is the one-touch low idle switch which operates only when no demand is placed on the hydraulic system.

The first depression (ON) of the switch decreases the engine rpm from the no load speed setting (either 100 rpm or 1300 rpm below high idle) to a setting of approximately 950 rpm for the 320 Excavator or 850 rpm for the 330. The second depression (OFF) of the switch returns the engine speed setting to the previous no load value.

If a hydraulic load is applied while the engine speed setting is at 950 or 850 rpm, the setting will increase to the engine speed dial setting.

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32

• Normal operation

• Speed dial backup switch in "AUT" position

• Pump control backup switch in "AUT" position

• Backup systems controlled individually

BACKUP SYSTEM CIRCUITS

ENGINE SPEED DIAL BACKUP SWITCH 24V GOVERNOR ACTUATOR DRIVE CIRCUIT 24V PUMP CONTROL BACKUP SWITCH GOVERNOR ACTUATOR ENGINE SPEED CHANGE SWITCH ECU PRV DRIVER PRV BACKUP RESISTOR BACKUP DETECTION M PRV AUT MAN AUT TOR RAB TOR Backup Systems

This schematic shows the two backup systems during normal machine operation. The controller sends electrical signals through the engine speed dial backup switch to the governor actuator motor. Notice that the engine speed dial backup switch is in the "AUT" position. The engine speed change switch is in the spring loaded center position.

The controller also sends signals through the pump control backup switch to the PRV. Notice that the pump control backup switch is in the "AUT" position. Also, the backup resistor is connected to only the backup switch at this time.

The engine speed dial and pump control backup are separate systems and are controlled individually.

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33

• Speed dial backup switch in "MAN" position

• Governor actuator motor disconnected from speed dial

• Speed change switch is activated

BACKUP SYSTEM CIRCUITS

ENGINE SPEED DIAL BACKUP SYSTEM ON

ENGINE SPEED DIAL BACKUP SWITCH 24V GOVERNOR ACTUATOR DRIVE CIRCUIT 24V PUMP CONTROL BACKUP SWITCH GOVERNOR ACTUATOR ENGINE SPEED CHANGE SWITCH ECU PRV DRIVER PRV BACKUP RESISTOR BACKUP DETECTION M PRV AUT MAN AUT TOR RAB TOR

In this schematic, the engine speed dial backup switch has been moved to the "MAN" position which disconnects the governor actuator motor from the engine speed dial. At the same time, the speed change switch is inserted into the circuit. Moving the speed change switch left or right will send power to the motor to either increase or decrease engine speed.

NOTE: When only the engine speed dial backup system is ON, the operator will see an "A" in the three digit display on the monitor panel. (The "A" means the governor actuator motor circuit is open.)

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34

• Pump control backup switch in "Tortoise" position

• Backup resistor connected to PRV

• PRV sends constant power shift pressure to pumps

BACKUP SYSTEM CIRCUITS

ENGINE SPEED DIAL BACKUP SWITCH 24V GOVERNOR ACTUATOR DRIVE CIRCUIT 24V PUMP CONTROL BACKUP SWITCH GOVERNOR ACTUATOR ENGINE SPEED CHANGE SWITCH ECU PRV DRIVER PRV BACKUP RESISTOR BACKUP DETECTION M PRV AUT MAN AUT TOR RAB TOR

PUMP CONTROL BACKUP SYSTEM ON

In this schematic, the pump control backup switch has been moved to the "Tortoise" position which disconnects the pump control from the

controller and connects the backup resistor circuit to the PRV. The PRV receives a constant signal of approximately 0.5 amps and sends a constant power shift pressure to the hydraulic pumps. At this time, pump output is approximately that of Power Mode II.

NOTE: When only the pump control backup system is ON, the operator will see an “H” in the three digit display on the monitor panel. When both the speed dial and pump control backup systems are ON, a "U" will be shown in the three digit display.

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35

• Two level diagnostic capability

• Data Mode provides information on eight key systems • Information displayed in three digit LCD's

PERFORMANCE

MONITOR

SERVICE

FUNCTIONS

AEC

SERVICE FUNCTIONS

A comprehensive two level diagnostic capability is built into the 320/330 controller. The first level (called the "Data Mode") will be explained in detail since this level will be used most often. The Data Mode provides status information on the function of eight key systems within the

machine. The POWER, LIGHT, TRAVEL SPEED and WIPER LED's are used as a guide to access the eight channels of information in the Data Mode. The information from these eight channels will be displayed in the three digit LCD's on the monitor panel.

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36

• Accessing the Data Mode

• Push and hold ALARM CANCEL button until LED flashes

• Push POWER button until Power Mode III LED flashes

• Data Mode is accessed

• To exit, push ALARM CANCEL button or turn key start switch OFF

PERFORMANCE

MONITOR

ACCESSING THE

DATA MODE

AEC

Data Mode

To access and view the first channel of information, the engine can either be running or shut down. If the engine is running, however, some

machine systems can be observed in operation. In this service mode, all of the LCD gauges and warning indicators will continue to function normally and all machine functions can be controlled.

First, push and hold the ALARM CANCEL button until its LED begins to flash. Next, while still pushing the ALARM CANCEL button, push the POWER button until the LED for Power Mode III begins to flash. Do not hold the POWER button too long or another of the eight LED's will flash. If this condition occurs, continue to push the ALARM CANCEL and POWER buttons simultaneously until the LED for Power Mode III again flashes. The Data Mode has now been accessed and the eight channels of information can be viewed.

To exit this service mode at any time, either push the ALARM CANCEL button for more than two seconds or turn the key start switch OFF.

LHPH 320 330 Electronic Control Unit

MEETING GUIDE 621

SLIDES AND SCRIPT

AUDIENCE

CONTENT

OBJECTIVES

REFERENCES

PREREQUISITES

SUPPLEMENTARY TRAINING MATERIAL

TABLE OF CONTENTS

3

3

3

3

2

2

2

2

0

0

0

0

//

//

3

3

3

3

3

3

3

3

0

0

0

0

H

H

H

H

Y

Y

Y

Y

D

D

D

D

R

R

R

R

A

A

A

A

U

U

U

U

II

II

C

C

C

C

E

E

E

E

X

X

X

X

C

C

C

C

A

AV