SERV2633 - - Monitor & Implement - Text - 992G

7/23/2019 SERV2633 - - Monitor & Implement - Text - 992G

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Service Training SERV2633-01

April 2002

TEXT REFERENCE

PART OF TECHNICAL INSTRUCTION MODULE SERV2633

992G WHEEL LOADER

MONITORING AND IMPLEMENT SYSTEMS


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TABLE OF CONTENTS

INTRODUCTION ..................................................................................................................3

MONITORING SYSTEM......................................................................................................4

VIDS/VIMS Major Components ......................................................................................7

Warning Operation..........................................................................................................20

Onboard Applications .....................................................................................................22

Data Events .....................................................................................................................24

Maintenance Events ........................................................................................................27

Hardware and Software Requirements ...........................................................................29

ELECTRO-HYDRAULIC IMPLEMENT SYSTEM...........................................................31

Implement Electronic Control System............................................................................33

Implement Electronic Control System Components.......................................................35

Pilot Hydraulic System ...................................................................................................44

Main Hydraulic System ..................................................................................................55

Variable Implement Pump Control Schematics ..............................................................60

Implement Control Valve Operation...............................................................................65

Electro-Hydraulic Implement System Schematics .........................................................67

Implement Hydraulic Schematics ...................................................................................75

FAN DRIVE SYSTEM.........................................................................................................91

Fan Drive System Components ......................................................................................93

Fan Drive System Schematics ........................................................................................96

CONCLUSION...................................................................................................................101

VISUAL LIST ....................................................................................................................102


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Introduce course

1

INTRODUCTION

This presentation discusses the component locations, systems operation,and testing and adjusting procedures for the Monitoring and Implement

Systems on the 992G Wheel Loaders. When discussing the monitoring

system, block diagrams and component illustrations will be used to

describe the system operation and features. When discussing the

hydraulic systems operation, both sectional view and graphic symbol

schematics will be used. The hydraulic systems will be explained by

tracing oil flow from the tank, through the system and back to the tank.

999922GGWWHHEEEELLLLOO AADDEERR

MMOO NN IITTOORRIINNGG AANNDDIIMMPPLLEEMMEENNTTSSYYSSTTEEMMSS

2002 Caterpillar Inc.


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SENSORS

ENGINEECM

SERVICE

LAMP MESSAGE CENTER

MODULEQUAD GAUGE

MODULE

KEYPAD

MODULE

SENSORS

INTERFACE

MODULE

INTERFACE

MODULE

SENSORS

VIMS

SERVICE TOOLAND

SOFTWARE

CAT DATA LINK

SERVICE

KEYSWITCH

ACTION

LAMP

ACTION

ALARM

ELECTRONIC

TECHNICIAN

VIMS MAIN MODULE

DISPLAY

DATA LINK

VIMSRS-232PORT

CAT DATA LINK

VITAL INFORMATIONDISPLAY/MANAGEMENT

SYSTEM(VIDS/VIMS)

SPEEDOMETER/TACHOMETER

MODULE

3F12 MPHkm/h

KEYPAD

DATA LINK

OK

0

1 2 3

4 5 6

7 8 9

ABC

IDDEF

G HI J K L M N O

PRS T UV W X Y

P 1 P2 P 3

IMPLEMENT ECM POWER TRAIN ECM

VIMS

ONLY

MONITORING SYSTEM

The 992G Wheel Loader is equipped with the Vital Information Display

System (VIDS) or the optional Vital Information Management System

(VIMS). The VIDS and VIMS are composed of modular onboard

electronics which have the ability to acquire data, perform analysis, store

information, and display data. When discussing characteristics that relate

to both the VIDS and VIMS, the system will be called VIDS/VIMS.

When equipped with source code software, the VIDS/VIMS main module

recognizes (through configuration software) the machine on which it is

installed and knows which components are present.

The various electronic modules communicate with each other in addition

to receiving information from other machine electronic control modules

(such as the Engine ECM, Power Train ECM, etc.).

Objective 1

Visuals 2 - 15

Distribute Lab A

Worksheets

Explain operation


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The optional VIMS uses both onboard and offboard hardware and

software to display information to the machine operator in addition to

supplying information on machine systems to dealer and customertechnical staff. This information will assist in minimizing downtime and

operating costs.

To successfully service machines equipped with the VIDS, the service

technician needs to become proficient in accessing the information

through the onboard keypad and message center. To successfully service

machines equipped with the VIMS, the service technician must also be

able to use a service tool (PC) to perform other required tasks.


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VIDS/VIMS alerts

operator of abnormal

conditions

Two types of events

stored by VIDS/VIMS:

- Data event

- Maintenance event

VIDS/VIMS

The VIDS/VIMS is designed to alert the operator of an immediate or

impending abnormal condition in one or more of the machine systems that

are being monitored. These abnormal conditions are called "events."

Two types of events are recognized and stored by the VIDS/VIMS. One

event is called a "data" event and alerts the operator to an abnormal

machine condition (such as hydraulic oil temperature too high). The other

event is called a "maintenance" event, which alerts the operator to a faultcondition which is caused by a malfunction (fault) in one of the electronic

devices (such as a hydraulic temperature sensor being used to monitor a

machine system). A more detailed explanation of "events" will be

covered later in the module.

In addition to alerting the operator of an abnormal condition, a service

lamp is installed externally on the machine to alert service or maintenance

personnel that an "event" is present, and diagnostic information regarding

the event is available in the VIDS/VIMS.

The major modules that comprise the VIDS/VIMS will now be covered in

detail.


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4

VIDS/VIMS Major Components

The quad gauge module contains four gauges which provide informationon measured machine parameters (such as temperature, pressure, and fuel

level). Consult the 992G Wheel Loader Operation and Maintenance

Manual (Form SEBU7009) for the specific machine parameters.

The VIDS/VIMS uses electronic input devices (sensors) to measure the

parameter, calculates an output signal, and sends the signal to the gauge

cluster where the parameter is displayed.

The quad gauge is configured for a specific machine (shovel, off-highway

truck, or wheel loader) and the actual machine parameter is representedon the gauge by a graphic symbol.

Quad gauge module

- Four measured

machine parameters


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Speedometer/

tachometer module

displays ground

speed, engine speed,

and transmission gear

and direction

0

5

1015

20

25

30

X100

The speedometer/tachometer module displays ground speed in km/h

(mph), engine speed, and transmission gear and direction. The electronic

input devices used for this information will be discussed later.


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Message center

module contains:

- Data logger indicator

- Alert Indicator

- Universal gauge

- Gauge warning area

- Message center

ENGINE TEMP [110]60 Deg F

DATA

LOGGER

INDICATOR

ALERT

INDICATOR

UNIVERSAL

GAUGE

GAUGE

WARNINGAREA

MESSAGE

AREA

The message center module contains a Data Logger indicator, alert

indicator, universal gauge, gauge warning area, and message area.

The Data Logger indicator (series of four dots) in the upper right corner

scrolls when the Data Logger is turned on. The dots are not present when

the Data Logger is stopped or when the Data Logger is initiated with the

offboard service tool (PC).

The alert indicator notifies the operator of an abnormal machine

condition. The condition could be caused by the VIDS/VIMS detecting a

"data" or "maintenance" event. The alert indicator receives a signal from

the main module causing the indicator to flash. The alert indicator will be

discussed in detail in the warning operation section of this presentation.


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The message area shows the value for the parameter shown on the

universal gauge. For sensor-type parameters (non switch-type inputs), the

gauge shows the actual value for the parameter being measured. Thegauge can also be used to observe any of the machine parameters by

entering the parameter number on the keypad and pressing the "gauge" on

the keypad. The universal gauge allows the operator or service technician

to select their "favorite" parameter or to monitor a troublesome parameter

which has not exceeded its limit.


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Message area

displays machine

information

LOW ENGINE OIL PRESSURE

SHUT DOWN SAFELY

OIL PRESSURE ERROR

CALL SHOP

0745 267

DATA EVENT

MAINTENANCE EVENT

DEFAULT SCREEN

The message area displays information regarding the condition of the

machine. The display of information is prioritized and includes data

events, maintenance events, operator or service technician requested data,

and default information.

The message area provides two lines of text (twenty characters per line) to

display information to the operator or service technician. When an event

(data or maintenance) occurs, information relating to the out-of-

specification parameter is displayed on the first line to identify the nature

of the abnormal condition. The following is an example of information

that may appear in the message area if an abnormal data event occurs:

LOW ENGINE OIL PRESSURE

SHUT DOWN SAFELY


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Events displayedaccording to priority

Default information

includes time of day

and machine servicehours

Information on the second line displays the desired operator response to

the condition.

If a maintenance event occurs, the message area will display the

parameter followed by the word ERROR. The second line will give the

operator instructions regarding the condition. The following is an

example of information that may appear if a maintenance event is active:

If more than one event is present, the event information will be displayedaccording to priority. The priority process will be discussed in the

warning operation section of this module.

The message area can also display requested data such as event lists or

active system events in Module Identification (MID), Component

Identification (CID), and Failure Mode Identifier (FMI) formats.

If no data has been requested by the operator and no event messages are

active, default information will be presented in the message area. The

default information includes time of day and machine service hours. Thefollowing is an example of default information displayed in the message

area:

If a problem exists in either the source code or configuration software, the

time of day and service meter hours will not be displayed after start-up.

OIL PRESSURE ERROR

CALL SHOP

0745 267


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Keypad used to

communicate with

VIDS/VIMS

Six additional input

keys:

- OK key

- ID key

- Universal gauge key

- Left and right arrow

keys

- F1 key

- F2 and F3 keys

OK

0

1 2 3

4 5 6

7 8 9

ABC

ID

DEF

GHI JKL MNO

PRS TUV WXY

F1 F2 F3

The keypad allows the operator or service technician to communicate with

the VIDS/VIMS by entering numeric information. The numeric section of

the keypad (keys 0 to 9) can be used to initiate service procedures, enter

operator identification codes, acknowledge events, and respond to

VIDS/VIMS inquiries (such as Data Logging information).

An indicator (upper right corner of keypad) flashes each time a key is

pressed to inform the operator or service technician that the keystroke was

accepted.

Eight additional keys are available for inputting information. They are:

OK Used to complete keypad entries and to acknowledge

events.


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Used by the operator to enter his or her identification or

badge number into the VIDS/VIMS memory.

Used to display the value of any measured parameter.

When the gauge key is pressed, line one of the message

area displays the parameter name and parameter

number, and line two displays the parameter value and

unit of measure.

This information is presented for one parameter at a

time. To scroll through the remaining parameters

requires using the Forward and Backward arrow keys.

A specific parameter can be displayed without using

the Forward or Backward keys by entering the number

of the parameter and then pressing the Gauge key. The

requested information will remain displayed until the

OK key is pressed, which returns the message center

module to the default mode.

If an event occurs while a parameter is being displayed,

the parameter information will be overwritten with the

event information.

Allows the operator or service technician to scroll

forward or backward through the information shown in

the message area.

Allows the operator or service technician to request

additional information regarding data and maintenance

events. If a data event is displayed, pressing the F1 key

will replace the information shown on line two of the

message area with the event value and units.

If a maintenance event is displayed, pressing the F1

key will replace the information shown on line two

with MID, CID and FMI information (example: MID

049, CID 0168, FMI 04).

Allows the operator to clear the last non stored bucket

load from memory.

Allows the operator to select a new loader delay code.

ID

F1

F2

F3


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Main module is

"heart" of VIDS/VIMS

Four sections of

module functions

- Data links

- Inputs

- Outputs

- Display

VIDS/VIMSMAIN MODULE

The main module is the "heart" of the VIDS/VIMS and, as such, makes

decisions based upon input signals received from various other electronic

control modules on the machine. A 37 pin connector on the module

connects the necessary harness wiring to the input and output devices.

The overall function of the main module can be described in four sections.

The four sections are labeled: Data Links, Inputs, Outputs, and Display

Components.

Data Links The main modules incorporate four different

data links. One is the CAT Data Link which

is a bi-directional link allowing the VIDS/VIMS to

communicate with other onboard electronic

controls. The CAT Data Link uses two

communication paths to ensure uninterrupted

communications in the event of an open in onepath.


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The second and third data links are RS-232 data

links. These two communication links are separate.

One of the links has two communication ports, onein the cab and the other mounted outside the cab to

allow easy access for the service technician.

The second RS-232 Data Link allows the

VIDS/VIMS to communicate with an offboard

service tool (PC).

The third RS-232 Data Link allows the VIMS to

communicate through two-way radio

communications with other offboard systems.

The fourth Data Link is an instrumentation link that

connects the various display components to the

main module.

Inputs Inputs to the VIDS/VIMS main module include a

switch-type input from the key start switch, open or

grounded switch-type inputs from switches used tomonitor machine events, a lighting sensor to inform

the main module when the dash panel lamps are

turned ON, a keypad input to receive information

from the keypad, and an input that measures system

voltage at the VIDS/VIMS circuit breaker.

Outputs The main module sends an output signal to the

action lamp if a Category 2 or 3 warning is present.

The module also sends a signal to the action alarm

to sound an alarm if a Category 3 warning is

present. The main module provides power for all

the display components, and turns a service light

ON (steady) to alert maintenance personnel if an

active system event is present. The light will flash

if an abuse related event is present.

Display The main module supplies information to all the

display components (gauge cluster,

speedometer/tachometer, message center andkeypad). The display components alert the

operator to machine conditions.


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Interface modules:

- One with VIDS

- Two with VIMS

- Send output

information to

VIDS/VIMS mainmodule

VIDS/VIMS

INTERFACE

MODULE

The exact number of interface modules installed on a Caterpillar machine

will be determined by the configuration software. A 992G with VIDS has

one interface module. The same machine with VIMS has two modules.

Although each module functions in the same manner, each module will be

assigned its own individual MID. The MID number associated with each

module is determined by the machine harness code connections on each

module.

The interface modules receive inputs from the sensors and switches,

process the information, and then send an output over the CAT Data Link

to the main VIDS/VIMS module where the information is processed and

sent to the various display components.


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Interface module

inputs:

- Sensor inputs

- Switch inputs

- CAT Data Link

The following is a brief description of the interface module inputs:

Sensor Inputs The VIDS/VIMS uses sensors to provideinformation on the various measured parameters.

The sensors used by the VIDS/VIMS are either pulse

width modulation or frequency type. The operation

of the sensors will be discussed later in this module.

Switch Inputs Each module is capable of processing information

from thirteen switches. Eight of the switch inputs

are uncommitted and provide the module with

machine system status information (open or

grounded). The information is received frompressure switches, temperature switches, flow and

level switches, and position switches.

One switch input is a committed input received from

the key start switch and provides the module with

battery voltage on contact No. 1 of the 40 pin

connector when the key switch is in the ON position.

The remaining four inputs are programming type

inputs and, as such, are harness code inputs that tell

the main VIDS/VIMS module which interface

module it is communicating with. A combination of

grounded and open harness code inputs determines

the unique MID code for each module installed on

the machine.

CAT Data Link This Data Link provides the VIDS/VIMS with both

an input and output. Its primary purpose is to

provide a high speed ring that allows data to be

shared by all electronic controls used on the

machine.

Each VIDS/VIMS module has two identical Data

Links that work independently. The two

communication paths allow the VIDS/VIMS to

continue operating even if one of the Data Links

becomes damaged. The CAT Data Link system is

bi-directional (input/output) and also performs as

an output device.


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Additional modules

may communicate

with VIDS/VIMS

- Engine ECM

- Implement ECM

- Power Train ECM

The interface module(s), in addition to receiving and processing

information from individual electronic devices (sensors and switches),

provide outputs. The primary outputs are delivered through the CAT DataLink to the main VIDS/VIMS module. The interface module provides

two solenoid outputs which can be used to energize solenoids or relay

coils, and also provides two regulated voltage outputs that are used to

power the sensors. The regulated outputs are +8 and +5 DCV.

Depending on the machine configuration and software, numerous other

modules can be connected to the VIDS/VIMS. Some of the additional

electronic control modules that may be installed are:

Engine ECM

Implement ECM

Power Train ECM

Each additional control module processes its own input devices and uses

the CAT Data Link to communicate with the VIDS/VIMS.


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Warning operation

- Warning Category 1



Category 1

Category 2Category 3

WARNING OPERATION

Warning Operation

The VIDS/VIMS monitors designated machine systems and notifies the

operator of immediate or impending problems. The warning categories of

the VIDS/VIMS are the same as those used with the Computerized

Monitoring System (CMS). The inputs and internal operation of the

controls differ, but the outputs of the system remain unchanged.

The operator receives the following types of warning:

Warning Category 1 - Alert indicator flashes. No

immediate action required by the

operator. (Requires servicing by the

end of the shift.)


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VIDS/VIMS triggers

warning when a data

or maintenance event

occurs

Warning Category 2 - Alert indicator flashes and the

action lamp flashes. Machine

operation should be changed ormaintenance performed.

Warning Category 3 - Alert indicator flashes, action lamp

flashes and action alarm sounds.

Operator should perform an

immediate safe engine shutdown.

The VIDS/VIMS triggers the warning operation when a data or

maintenance event occurs. The abnormal condition is sensed by the

interface module, processed, and then sent to the main module where theappropriate warning category is determined and relayed to the operator

through the alert indicator (flashing), action lamp (flashing), or the action

alarm (sounding).

Warning inputs are provided by switches and sensors. In some cases,

more than one input is needed to trigger a specific warning category. The

VIDS/VIMS identifies the warning category displayed according to active

events. If more than one event is active, each event will be scrolled on

the message area in five second intervals. If a Category 3 (most severe)

event is active, Category 1 and 2 events cannot be scrolled.

Although the VIMS warning categories are the same as those used on

other systems (EMS and CMS), some changes have been made in the area

of operator awareness. The VIMS documents when the operator

acknowledges the fault. When a Category 1 or 2 event becomes active,

the operator can acknowledge the event by pressing the OK key on the

keypad. Depending on the nature of the event, the warning category may

be cancelled for a specific period of time. After the time interval is

exceeded, the warning category will again be displayed. Category 3

events cannot be cancelled by the operator.


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Two categories ofevents:

- Data events

- Maintenance events

VIDS/VIMS ONBOARD APPLICATIONS

Onboard Applications

The VIDS/VIMS onboard components not only display information

relating to machine parameters but, as stated earlier, also alert the operator

of an impending event (abnormal condition) in one or more of the

machine systems being monitored. These abnormal conditions are called

"events." Two categories of events can occur: data events and

maintenance events.

Data events indicate that the machine is operating outside of normal

limits. A data event may occur because a specific parameter detects an

abnormal condition. An example of a data event could be low hydraulic

oil level or low fuel level.


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VIDS/VIMS alerts

operator of eventsThe VIDS/VIMS will alert the operator with the appropriate warning

category. The operator must acknowledge the event and then take the

appropriate action required. If more than one event is present of the samecategory, the message center will alternate between each event.

Maintenance events reflect the VIDS/VIMS self-diagnostic capabilities.

If the VIDS/VIMS detects an event condition in one or more of its

electronic monitoring devices (switches, sensors, etc.), a maintenance

event will be immediately displayed on the message center and the

operator will be alerted by the appropriate warning. The service

technician can retrieve additional diagnostic information on the detected

fault by pressing the F1 key on the keypad or by accessing the

VIDS/VIMS through the use of a service tool (PC).


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Data events

VOLTAGE TOO LOW

SHUT DOWN SAFELY

Data Events

The message area provides two lines (twenty characters per line) to

display information to the operator or service technician. When a data

event occurs, a message is displayed on the first line to identify the type of

abnormal condition. The second line indicates the required operator

action.

In the above example, the operator is alerted to a Category 3 warning.

The alert indicator and action lamp will flash and the action alarm will

sound. The message center directs the operator to shut the machine down

safely.

VOLTAGE TOO LOW

SHUT DOWN SAFELY


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Troubleshooting data

events

The VIDS/VIMS detected a critically low system voltage (less than 23.0

Volts). Continued machine operation with low system voltage could

possibly cause the electronic controls installed on the machine to shutdown.

The service technician can easily investigate the data event using the

universal gauge as a service tool. Entering the parameter number of 140

and pressing the Gauge key on the keypad will display the parameter

name and number on the first line and the parameter value and units on

the second line. Example:

When a data event occurs and the service technician is requested to

diagnose the malfunction, it is important that all the facts concerning the

reported complaint are gathered. The advanced capabilities of the

VIDS/VIMS allow the system to distinguish between actual problems

with the machine or its components and conditions caused by

inappropriate operation (abuse). The VIDS/VIMS will distinguish

between the types of problems and maintain a count of occurrences in

memory.

To effectively diagnose data events may require the service technician to

use all available VIDS/VIMS resources. The message center and keypad

may be used to display event information such as event statistics, event

list and acknowledge events. To observe the above information, the

service technician must initiate the appropriate service operation.

VOLTAGE [140]

22.5 VOLTS


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On the VIMS, the event information can be downloaded using a service

tool (PC). Downloading an event list will provide the service technician

with the following types of event information:

Machine serial number

Service Meter Units (SMU)

Description (event name)

Date of event

Time event started

Minimum or maximum limits (value where a warning occurs)

Units of measurement

Actual event value

Event duration

Acknowledgment time

It may also be necessary to use other types of stored information in

solving machine abnormalities.

INSTRUCTOR NOTE: For a more detailed explanation of other

available resources, consult the Technical Instruction Module "Vital

Information Management System--Introduction" (Form SEGV2597).


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Maintenance events

OIL PRESSURE ERROR

CALL SHOP

Maintenance Events

The message area provides two lines (twenty characters per line) to

display information to the operator or service technician. When a

maintenance event occurs, information identifying a specific parameter

has "error" displayed on the first line and information giving the operator

instructions appears on the second line. Example:

With the above information displayed in the message area, additional

diagnostic information can be displayed on the second line by pressing the

F1 key on the keypad.

OIL PRESSURE ERROR

CALL SHOP


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Diagnostic codes

displayed on second

line

The display will now show the MID, CID and FMI codes for the active

maintenance event. Example:

The diagnostic codes displayed on the second line provide valuable

information to the service technician. The MID identifies which

electronic control has diagnosed the event. Since the VIMS has the

ability to receive maintenance event information from other controls over

the CAT Data Link, it is necessary to establish the source of the event.

Each electronic control module installed on the machine has its own

unique identifier. Always refer to the appropriate service manual for the

proper MID identifier codes.

To successfully diagnose, troubleshoot, and repair VIDS/VIMS

malfunctions will require the service technician to use all resources

available (service manuals, wiring schematics, handouts etc.).

Additionally, the service technician needs to be able to use the diagnostic

tooling that is available for all electronic control systems. To diagnose

VIDS/VIMS related faults, the service technician needs to be totally

proficient in reading and interpreting the electrical wiring schematics and

in the use of a digital multimeter.

OIL PRESSURE ERROR

MID036 CID0100 FMI03


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SOFTWARE

HARDWARE

Hardware and Software Requirements

To successfully run the VIMS, the following computer hardware and

software is needed.

The recommended service tool and software configurations are:

Computer with a Pentium II, 266 MHz processor

32 Mb of RAM

2 Gb hard drive space available

12X speed CD-ROM

3.5" 1.44 Mb diskette drive


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Super VGA color monitor or display

RS232 port with 16550AF UART

Built in pointing device or mouse

Microsoft Windows NT, 2000, 98, or 95 operating system

NOTE: Caterpillar provides a well trained Technical Support

Hotline for assistance. Help can be reached on the PC Software

Hotline Monday through Friday, between the hours of 8:00 AM and4:00 PM Central Standard Time (CST). Call 1-800-THE-PCDR

(within in the U.S. and parts of Canada), and 309-674-5290 (from all

other locations). Use 309-673-1403 for FAX and, if connected to the

Caterpillar Network, the User ID is: THEPCDR, Address:

ADCCHOST.

INSTRUCTOR NOTE: At this time, introduce and perform "Lab A:

VIDS/VIMS Monitoring System Information Access." This lab will

reinforce the material discussed in the preceding visual presentation.Introduce Lab A


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IMPLEMENT

HYDRAULIC

PUMPS

PILOT

PUMP

VARIABLE PUMP

SOLENOID VALVE

PILOT

RELIEF

VALVE

IMPLEMENTELECTRONIC

CONTROL

MODULE

PILOT CONTROL

LEVER MODULE

MAIN CONTROL

VALVE ASSEMBLY

TILT

CYLINDER

HYDRAULIC

TANK

LIFT LINKAGE

POSITION SENSOR

LIFT

CYLINDER

TILT LINKAGE

POSITION SENSOR

ELECTRONIC SYSTEM MAIN HYDRAULIC SYSTEM

PILOT HYDRAULIC SYSTEM COMMON TO BOTH SYSTEMS

ELECTRO-HYDRAULIC IMPLEMENT SYSTEM

ELECTRO-HYDRAULIC IMPLEMENT SYSTEM

Shown are the major components of the electro-hydraulic implement

system. The electro-hydraulic implement system is pilot operated. The

pilot system controls the functions of the main control valve. The pilot

system consists of the electronic system and the pilot hydraulic system.

The electronic system components (brown) are the pilot control lever

module, the Implement Electronic Control Module (ECM), the variable

pump solenoid valve, the tilt linkage position sensor, and the lift linkage

position sensor.

Objective 2

Visuals 16 - 25

Objective 11

Visuals 16 - 35

Distribute Lab B

Worksheet

Identify components:

- Electronic system

- Pilot hydraulic

system

- Main hydraulic

system

- Common to both

systems


32/103

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Electronic system

components

Pilot hydraulic system

Main hydraulic system

Tank common to both

hydraulic systems

Electronic system components not shown are the tilt lever, lift lever, tilt

sensor, lift sensor, bucket kickout detent solenoid, lift kickout detent

solenoid, lower kickout detent solenoid, the implement lockout switch,the pilot on/off solenoid valve, and the pilot control actuator solenoids.

The pilot hydraulic system (orange) consists of the pilot pump, the

manual lower valve, the pilot relief valve, the pilot on/off valve (part of

the main control valve assembly), and the pilot control actuators (part of

the main control valve assembly).

The main hydraulic system (red) consists of the fixed pump, the variable

pump, the fixed pump relief valve (part of the main control valve

assembly), the variable pump relief valve (part of the main control valveassembly), the main control valve assembly, two lift cylinders, and the tilt

cylinder.

The hydraulic tank (green) is common to both hydraulic systems.

INSTRUCTOR NOTE: The color codes used for hydraulic oil

throughout this presentation are:

Red - System or high pressure

Red and White Stripes - Reduced pressure

Orange - Pilot pressure

Blue - Blocked oil

Green - Tank or return oil


33/103

17

SERV2633-01 - 33 -

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LIFT/LOWER/TILTKICKOUT SWITCH

IMPLEMENTLOCKOUT SWITCH

TILT LINKAGESENSOR

LIFT LINKAGE

SENSOR

TILT LEVERSENSOR

LIFT LEVERSENSOR

PILOT ON/OFF SOLENOID

BUCKET KICKOUT DETENT COIL

LIFT RAISE KICKOUT DETENT COIL

LIFT LOWER KICKOUT DETENT COIL

VARIABLE PUMP SOLENOID

TILT BACK SOLENOID NO. 1

TILT BACK SOLENOID NO. 2

TILT DUMP SOLENOID NO. 1

TILT DUMP SOLENOID NO. 2

LIFT LOWER SOLENOID NO. 1

LIFT LOWER SOLENOID NO. 2

LIFT RAISE SOLENOID NO. 1

LIFT RAISE SOLENOID NO. 2

CAT DATA LINK

IMPLEMENT ELECTRONICCONTROL MODULE (ECM)

IMPLEMENT ELECTRONICCONTROL SYSTEM

INPUT COMPONENTS OUTPUT COMPONENTS

VARIABLEIMPLEMENT PUMP

PRESSURE SENSOR ANALOG TO DIGITAL

CONVERTER

Implement Electronic Control System

Shown is a block diagram of the Implement Electronic Control System.

The Implement Electronic Control Module (ECM) receives input signals

from the various sensors and switches. The Implement ECM processes

the input signals, makes decisions and provides a corresponding output

signal to the pilot solenoid valves and kickout solenoids. The Implement

ECM also communicates with other electronic control systems through

the CAT Data Link.

The Implement Electronic Control System consists of the following

components:

Lift lever sensor: Signals the Implement ECM the position of the lift

pilot control lever.

Explain component

functions


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Tilt lever sensor: Signals the Implement ECM the position of the tilt pilot

control lever.

Implement lockout switch: Signals the Implement ECM that the operator

wants the pilot control levers disabled.

Lift/lower/tilt kickout switch: Used to set the bucket tilt, lift raise and

lift lower kickout positions.

Lift linkage sensor: Signals the Implement ECM the position of the lift

arm relative to the machine.

Tilt linkage sensor: Signals the Implement ECM the position of the

bucket relative to the lift arm.

Pilot on/off solenoid: Controls the pilot on/off solenoid valve. The on/off

solenoid valve enables or disables the pilot hydraulic system.

Variable pump solenoid: Controls the variable pump solenoid valve.

The variable pump solenoid valve directs pilot oil from the main control

valve to the tank.

Tilt back solenoid: Controls the tilt back actuator. The tilt back actuator

directs pilot oil from the tilt back end of the main control valve spool to

the tank.

Tilt dump solenoid: Controls the tilt dump actuator. The tilt dump

actuator directs pilot oil from the tilt dump end of the main control valve

spool to the tank.

Lift lower solenoid: Controls the lift lower actuator. The lift lower

actuator directs pilot oil from the lift lower end of the main control valve

spool to the tank.

Lift raise solenoid: Controls the lift raise actuator. The lift raise actuator

directs pilot oil from the lift raise end of the main control valve spool to

the tank.

Lift lower kickout detent solenoid: Holds the lift lever in the LOWER

position.

Lift raise kickout detent solenoid: Holds the lift lever in the RAISE

position.

Bucket kickout detent solenoid: Holds the tilt lever in the TILT BACK

position.

CAT Data Link: Communication path to and from other electronic

control modules.


35/103

18

SERV2633-01 - 35 -

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LIFTLEVER

SENSOR

FIXEDPUMP

VARIABLEPUMP

SOLENOIDVALVE

VARIABLEPUMP

LEFTLIFT

CYLINDER

RIGHTLIFT

CYLINDER

TILTCYLINDER

SHUTTLEVALVE

PRESSUREREDUCING

VALVE

PILOTON/OFFVALVE

CHECKVALVE

BUCKETKICKOUTDETENT

SOLENOID

IMPLEMENTLOCKOUTSWITCH

RAISE/LOWER/TILTKICKOUT SET

SWITCH

TILT LINKAGEPOSITION SENSOR

LIFT LINKAGEPOSITION SENSOR

LIFTKICKOUTDETENT

SOLENOID

LOWERKICKOUTDETENT

SOLENOID

CATDATALINK

ELECTRO-HYDRAULIC

IMPLEMENT SYSTEM

RELIEFVALVE

PILOTRELIEF VALVE

PILOTPUMP

RELIEFVALVE

ELECTRONIC SYSTEM COMPONENTS

IMPLEMENTCONTROL

VALVE

IMPLEMENTCONTROL

VALVEELECTRONICCONTROLMODULE

TILTLEVER

SENSOR

MANUAL

LOWER

VALVE

BYPASSSWITCH

BYPASSSWITCH

BYPASSSWITCH

HYDRAULICACTUATOR

Implement Electronic Control System Components

The electronic system components (brown) are the implement lockout

switch, the raise/lower/tilt kickout set switch, the Implement ECM, the

tilt linkage position sensor, the lift linkage position sensor, the tilt lever

sensor, the bucket kickout detent solenoid, the lift lever sensor, the lift

kickout detent solenoid, the lower kickout detent solenoid, the hydraulicactuators (on the implement control valves), the pilot on/off valve, and

the variable pump solenoid valve.

Identify components


36/103

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1. Implement hydraulic

control levers

2. Tilt lever sensor

3. Horn

4. Right armrest

control lever

5. Control lever cover

19

The implement hydraulic control levers (1) are attached to the right

armrest assembly and move forward and rearward with the right armrest.

When the operator moves the tilt control lever, the tilt lever sensor (2)

sends a Pulse Width Modulated (PWM) signal to the Implement ECM.

Also shown are the horn (3) and the right armrest control lever (4).

Located below the control lever cover (5) are the lift lever sensor, the

bucket kickout detent solenoid, the lift kickout detent solenoid, and the

lower kickout detent solenoid.

1

2

4

1

5

3


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1. Raise, lower and tilt

kickout set switch

2. Dash light switch

3. Stairway light switch

4. Keypad

5. +12V connector

6. Electronic diagnosticconnector

7. Rimpull selector

8. Floodlight switch

9. Ride control switch

10. Quick-shift switch

11. Torque converterlockup switch

12. Heater and A/C fanswitch

13. Windshield wiperswitches

14. Key start switch

20

The raise, lower and tilt kickout switch (1) is located in the right side

panel. Depress the top of the switch to set the TILT kickout. Depress the

bottom of the switch to set the RAISE and LOWER kickouts.

When setting the bucket TILT kickout, move the bucket to the desired

position. Return the tilt lever to the HOLD position. Depress the top of

the kickout set switch for approximately one second and release.

When setting the RAISE kickout, raise the lift arm to the desired position.

Return the lift lever to the HOLD position. Depress the bottom of the

kickout switch for approximately one second and release.

When setting the LOWER kickout, lower the lift arm to the desiredposition. Return the lift lever to the HOLD position. Depress the bottom

of the kickout switch for approximately one second and release.

1 2 3 4 5

6

7891011

1213

14 1516 17


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15. Heater and A/Ccontrol switch

16. Start aid switch

17. Throttle lock switch

Also shown are the dash light switch (2), the stairway light switch (3), the

keypad (4), the +12V connector (5), the electronic diagnostic connector

(6), the rimpull selector (7), the flood light switch (8), the ride controlswitch (9), the quick shift switch (10), the torque converter lockup switch

(11), the heater and air conditioner fan switch (12), the windshield wiper

switches (13), the key start switch (14), the heater and air conditioner

control (15), the start aid switch (16), and the throttle lock switch (17).


39/103

21

SERV2633-01 - 39 -

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1. Lift linkage

position sensor

2. Tilt linkage

position sensor

The lift linkage position sensor (1) is bolted to the left side of the front

frame near the left side lift cylinder attachment pin. The lift linkage

position sensor constantly monitors the position of the lift linkage and

sends the lift linkage position information to the Implement ECM.

The tilt linkage position sensor (2) is bolted to the right side of the lift arm

near the tilt linkage attachment pin. The tilt linkage position sensorconstantly monitors the position of the tilt linkage and sends the tilt linkage

position information to the Implement ECM.

When the operator moves the lift lever or the tilt lever, the Implement

ECM analyzes the signal from the respective lever position sensor, the

signal from the lift linkage position sensor, and the signal from the tilt

linkage position sensor. The Implement ECM then sends a proportional

signal to the respective control valve solenoid.

1

2


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1. Implement ECM

2. Fuse panel

3. Key start relay

4. Main relay

5. VIDS interlock

module

6. VIDS/VIMS main

module

7. Power Train ECM

22

The Implement ECM (1) is located below the platform on the right side of

the cab.

Also shown are the fuse panel (2), the key start relay (3), the main relay

(4), the VIDS interface module (5), the VIDS/VIMS main module (6),

and the Power Train ECM (7).

1

2

3

4

6

5

7


41/103

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1. Pilot on/off

solenoid valve

2. Pilot control

actuators

3. Float valve

4. Fixed pump relief

valve

5. Pressure reducing

valve

23

The pilot on/off solenoid valve (1) is located in the front bottom section

of the main control valve center manifold.

When the pilot on/off solenoid is DE-ENERGIZED, pilot oil is blocked at

the pilot on/off solenoid valve.

When the pilot on/off solenoid is ENERGIZED, pilot oil flows to the pilot

control actuators.

Also shown are the pilot control actuators (2), the float valve (3), the

fixed pump relief valve (4), and the pressure reducing valve (5).

1

23

4

2

5


42/103

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1. Hydraulic actuator

solenoids

2. Lift cylinder head

end line relief valve

3. Tilt cylinder head

end line relief valve

24

The hydraulic actuator solenoids (1) control the movement of the

hydraulic actuators.

When the operator moves a control lever, the control lever sensor sends a

pulse width modulated (PWM) signal to the Implement ECM. The

Implement ECM analyzes the signals from the control lever sensor, the

lift linkage position sensor, and the tilt linkage position sensor. The

Implement ECM then sends a proportional signal to ENERGIZE the

respective pilot control actuator solenoid.

Also shown are the lift cylinder head end line relief valve (2) and the tilt

cylinder head end line relief valve (3).

1

3

2


43/103

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1. Variable pump

solenoid valve

2. Variable pump

valve solenoid

3. Implement pilot

relief valve

4. Implement pilot oil

pressure tap

Introduce Lab B

25

The variable pump solenoid valve (1) is located on the inside left frame

and to the rear of the implement pilot relief valve (3). The variable pump

solenoid valve controls pilot pressure to the load limiting control valve onthe variable pump control. The Implement ECM energizes the variable

pump valve solenoid (2) when the key start switch is ON. The Implement

ECM signal to the variable pump solenoid valve controls the pressure in

the load limit control valve. When the variable pump pressure increases

to 80% of maximum pressure, the load limit control valve moves and

sends oil pressure to the large actuator to destroke the pump.

Also shown is the implement pilot oil pressure tap (4).

INSTRUCTOR NOTE: At this time, introduce and perform "Lab B:Electronic Implement Control System Component Identification

Quiz." This lab will reinforce the material discussed in the preceding

visual presentation.

1 23 4


44/103

26

SERV2633-01 - 44 -

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Objectives 3 and 5

Visuals 26 - 35

Distribute Lab C, D, E, F

and G Worksheets


- Tank

- Pilot pump

- Pilot relief valve

- Pilot on/off valve

- Check valves

- Manual lower valve

- Pressure reducing

valve

- Hydraulic actuators

LIFTLEVER

SENSOR

FIXEDPUMP

VARIABLEPUMP

SOLENOIDVALVE

VARIABLEPUMP

LEFTLIFT

CYLINDER

RIGHTLIFT

CYLINDER

TILTCYLINDER

SHUTTLEVALVE

PRESSUREREDUCING

VALVE

PILOTON/OFFVALVE

CHECKVALVES

BUCKETKICKOUTDETENT

SOLENOID



SWITCH



RAISEKICKOUTDETENT

SOLENOID

LOWERKICKOUTDETENT

SOLENOID

CATDATALINK

ELECTRO-HYDRAULIC

IMPLEMENT SYSTEM

RELIEFVALVE

PILOTRELIEF VALVE

PILOTPUMP

RELIEFVALVE

PILOT SYSTEM COMPONENTS

IMPLEMENTCONTROL

VALVE

IMPLEMENTCONTROL


TILTLEVER

SENSOR

MANUAL

LOWER

VALVE

BYPASSSWITCH

BYPASSSWITCH

BYPASSSWITCH

HYDRAULICACTUATOR

Pilot Hydraulic System

The pilot hydraulic system components (orange) are the tank, the pilot

pump, the pilot relief valve, the pilot on/off valve, the check valves, the

manual lower valve, the pressure reducing valve, and the hydraulic

actuators. The hydraulic actuators are located on the implement control

valves.


45/103

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1. Hydraulic tank

2. Deck plate

3. Fill cap

4. Vent valve

5. Alternator breaker

6. Main circuit breaker

7. Starting/charging

analyzer connector

8. Service toolconnector

9. Running lamp

breaker

10. Key breaker

27

The implement hydraulic tank (1) is below the forward hinged deck plate

(2) on the right side of the machine. The tank has a fill cap (3) for filling

and adding oil and a vent valve (4) that protects the tank from excessivepressure and/or vacuum.

The tank also has three screens for return oil, an ecology-type drain valve,

and a sight glass for checking the oil level.

Also shown are the alternator breaker (5), the main circuit breaker (6), the

starting/charging analyzer connector (7), the service tool connector (8),

the running lamp breaker (9), and the key breaker (10).

NOTE: Oil change intervals and procedures are covered in the 992GOperation and Maintenance Manual (Form SEBU7009).

1

2

34

5

6 78 9 10


46/103

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1. Implement pilot

pump

2. Implement variable

displacement piston

pump

3. Pilot pump inlet

hose

4. Pilot pump outlet

hose

5. Pilot pump pressure

tap

28

The implement pilot pump (1) is a gear-type pump mounted on the front

of the implement variable displacement piston pump (2). Tank oil flows

through the pilot pump inlet hose (3) to the implement pilot pump. Pumpsupply oil flows through the outlet hose (4) to the implement pilot filter.

Also shown is the pilot pump pressure tap (5).

1

2

3

4

5


47/103

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1. Implement pilot oil

filter

2. Oil filter bracket

3. ROPS mounting

plate

4. Oil filter inlet hose

5. Oil filter outlet

hose

6. Oil filter bypass

switch

29

This view shows the implement pilot oil filter (1). The oil filter bracket

(2) is bolted to the right ROPS mounting plate (3). Supply oil from the

pilot pump flows through the oil filter inlet hose (4), the pilot filter andthe oil filter outlet hose (5), to the pilot relief valve (not shown).

The oil filter bypass switch (6) alerts the VIDS when oil is bypassing the

filter.

1

23

4

6

5


48/103

SERV2633-01 - 48 -

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1. Pilot relief valve

2. Variable pump

solenoid valve

3. Inlet hose

4. Outlet hose

5. Outlet hose

6. Return hose

7. Pilot relief valve

pressure sensor

30

The pilot relief valve (1) is bolted to the inside left frame forward of the

variable pump solenoid valve (2). Pilot oil from the pilot filter flows

through the inlet hose (3) to the pilot relief valve. The pilot relief valvelimits the pilot oil pressure to 2400 kPa (350 psi). Pilot pressure oil flows

through the outlet hose (4) to the on/off solenoid valve. Pilot pressure oil

also flows through the outlet hose (5) to the variable pump solenoid valve.

Pilot relief valve return oil flows through the return hose (6) to the tank.

The pilot relief valve pressure sensor (7) supplies pilot oil pressure

information to the VIDS/VIMS.

1

2

34 5

6

7


49/103

SERV2633-01 - 49 -

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Manual lower valve

(arrow)

31

The manual lower valve (arrow) is located at the articulation joint on the

front frame. The manual lower valve is used to lower the implement

when the engine and the machine electrical system are dead. The manuallower valve sends oil from the pressure reducing valve to the hydraulic

tank, allowing the implement lift cylinders to retract.


50/103

SERV2633-01 - 50 -

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1. Pilot control

actuators

2. Pilot on/off

solenoid valve

3. Lift rod end line

relief valve

4. Lift head end line

relief valve

5. Tilt rod end line

relief valve

6. Tilt head end line

relief valve

7. Fixed pump relief

valve

8. Float valve

32

The pilot control actuators (1) control pilot oil flow from the ends of the

main control valve spools to the tank.

Also shown are the pilot on/off solenoid valve (2), the lift rod end line

relief valve (3), the lift head end line relief valve (4), the tilt rod end line

relief valve (5), the tilt head end line relief valve (6), the fixed pump relief

valve (7), and the float valve (8).

1 1

3

2

4

56

7

8


51/103

33

SERV2633-01 - 51 -

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Explain the operation of

the pilot control

actuators.

CENTERINGSPRINGS

FEEDBACKSPRING

STABILIZINGSPRING

SPRINGRETAINER

MAINSPOOL

PILOTSPOOL

PILOT OILPORT

TANK OILPORT

ACTUATORSOLENOID

ACTUATORSOLENOID

MAIN CONTROL SPOOLSHOLD

SNAPRING

In the HOLD position, both solenoids for the pilot control actuators are

de-energized. When both solenoids are de-energized, the pilot spool

spools direct pilot oil to the ends of the main spool. The pilot pressure at

each end of the main spool and the force of the centering springs keep the

main spool centered in the control valve.

The centering springs and retainers help stabilize the movement of the

main spool. The stabilizing springs dampen the movement of the pilot

spools by holding the pilot spools in contact with the feedback springs.


52/103

34

SERV2633-01 - 52 -

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the pilot control

actuators.

CENTERINGSPRINGS

FEEDBACKSPRING

STABILIZINGSPRING

SPRINGRETAINER

MAINSPOOL

ACTUATORSOLENOID

PILOT OIL PORT

TANK OILPORT

PILOTSPOOL

ACTUATORSOLENOID

MAIN CONTROL SPOOLSLEFT SOLENOID ENERGIZED

SNAPRING

When the left solenoid is energized, the solenoid moves the pilot spool to

the right. The pilot spool directs the pilot oil on the left side of the main

spool to tank. This decreases the pilot oil pressure at the left end of the

main spool.

The right actuator solenoid is de-energized. When the solenoid is de-

energized, the feedback spring holds the pilot spool to the right. The pilot

spool directs pilot oil to the right end of the main spool. The pilot oil

pressure at the right end of the main spool moves the main spool to the

left. As the main spool moves to the left toward the left pilot spool, the

centering springs and the feedback spring are compressed.


53/103

35

SERV2633-01 - 53 -

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the pilot control

actuators.

CENTERINGSPRINGS

FEEDBACKSPRING

STABILIZINGSPRING

SPRINGRETAINER

MAINSPOOL

ACTUATORSOLENOID

PILOT OILPORT

TANK OILPORT

PILOTSPOOL

ACTUATORSOLENOID

MAIN CONTROL SPOOLSLEFT ACTUATOR BALANCED

SNAPRING

When the left solenoid is energized, the main spool moves to the left

which compresses the centering springs and the feedback spring. The

force of the feedback spring is equal to the force of the actuator solenoid

and the stabilizing spring. When the pilot spool moves far enough to the

left, the pilot oil port and the tank oil port are blocked. When the oil in

the actuator is blocked the main spool stops moving. The main spool will

stay in this balanced position until the current to the actuator solenoid

changes.

If the operator moves the implement control lever further in the same

direction, the Implement ECM will increase the duty cycle of the signal to

the actuator solenoid. This increases the current which increases the force

on the pilot spool. The pilot spool will move to the right which opens the

tank oil port. The decreased oil pressure inside the left actuator will allow

the main spool to move further to the left due to the pilot oil pressure on

the right end of the main spool. As the main spool moves to the left thefeedback spring will be compressed more and the feedback sequence

begins again.


54/103

SERV2633-01 - 54 -

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If the operator moves the implement control lever toward the centered

position, the Implement ECM will decrease the duty cycle of the PWM

signal to the actuator solenoid. This decreases the current whichdecreases the force on the pilot spool. The pilot spool will move to the

left which opens the pilot oil port and blocks the tank oil port.

The combined force of the pilot oil and the compressed centering springs

on the left side of the main spool will move the main spool to the right.

This will decrease the flow of oil to the implements. The force on the

pilot spool from the feedback spring decreases as the main spool moves to

the right. As the main spool moves to the right the force of the feedback

spring continues to decrease. The pilot spool continues to move to the

right until the pilot oil port and the tank oil port are blocked. When theforce of the feedback spring equals the combined force of the stabilizing

spring and the actuator solenoid, the spools will be balanced. The spools

will remain balanced until the current to the actuator solenoid increases or

decreases.


55/103

36

SERV2633-01 - 55 -

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Objective 4

Visuals 34 - 41


- Fixed pump

- Fixed pump relief

valve- Fixed pump

implement control

valve

- Variable pump

- Variable pump relief

valve

- Variable pump

implement control

valve

- Shuttle valve- Lift cylinders

- Tilt cylinder

LIFTLEVER

SENSOR

FIXEDPUMP

VARIABLEPUMP

SOLENOIDVALVE

VARIABLEPUMP

LEFTLIFT

CYLINDER

RIGHTLIFT

CYLINDER

TILTCYLINDER

SHUTTLEVALVE

PRESSUREREDUCING

VALVE

PILOTON/OFFVALVE

CHECKVALVE

BUCKETKICKOUTDETENT

SOLENOID



SWITCH



RAISEKICKOUTDETENT

SOLENOID

LOWERKICKOUTDETENT

SOLENOID

CATDATALINK

ELECTRO-HYDRAULIC

IMPLEMENT SYSTEM

RELIEFVALVE

PILOTRELIEF VALVE

PILOTPUMP

RELIEFVALVE

MAIN HYDRAULIC SYSTEM COMPONENTS

IMPLEMENTCONTROL

VALVE

IMPLEMENTCONTROL


TILTLEVER

SENSOR

MANUAL

LOWER

VALVE

BYPASSSWITCH

BYPASSSWITCH

BYPASSSWITCH

HYDRAULICACTUATOR

Main Hydraulic System

The main hydraulic system components (red) are the fixed pump, the

fixed pump relief valve, the fixed pump implement control valve, the

variable pump, the variable pump relief valve, the variable pump

implement control valve, the left and right lift cylinders, and the tilt

cylinder.


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1. Fixed pump

2. Supply hose

3. Suction hose

4. Implement pilot

pump

5. Variable pump

6. Supply hose

7. Case drain hose

8. Pump drivehousing

37

The main hydraulic system contains a fixed displacement, piston-type

pump (1) and a variable displacement piston-type pump (5).

Oil flows from the tank through a suction hose (3) to the fixed

displacement pump. The fixed displacement pump oil flows through the

supply hose (2) to the fixed pump implement control valve.

Oil flows from the tank through a suction hose (not shown) to the variable

displacement pump. The variable displacement pump supply oil flows

through the supply hose (6) to the variable pump implement control valve.

Also shown are the implement pilot pump (4), the case drain hose (7), and

the pump drive housing (8).

12

3

4

56

7

8


57/103

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1. Case drain filter for

the fixed pump

2. Case drain filter for

the variable pump

38

Shown is the case drain filter for the fixed pump (1) and the case drain

filter for the variable pump (2). The case drain filters remove

contaminants from the case drain oil before the oil enters the implementhydraulic tank.

1

2


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1. Main control valve

assembly

2. Right side control

valve

3. Tilt cylinder rod end

hose

4. Lift cylinder rod end

hose

5. Lift cylinder head

end hose

6. Tilt cylinder head

end hose

39

The main control valve assembly (1) is located in the front frame below

the boom.

The right side control valve (2) receives oil from the variable

displacement pump.

Also shown are the hose (3) to the rod end of the tilt cylinder, the hose (4)

to the rod end of the lift cylinders, the hose (5) to the head end of the lift

cylinders, and the hose (6) to the head end of the tilt cylinder.

1

2

3

4

5

6


59/103

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1. Lift cylinder

2. Tilt cylinder

3. Tilt linkage

position sensor

4. Right front brake

housing

5. Right front final

drive housing

40

When an implement is activated, oil from the implement control valve is

directed to the lift cylinders (1) and/or tilt cylinder (2).

Also shown are the tilt linkage position sensor (3), the right front brake

housing (4), and the right front final drive housing (5).

1 2

3

4

5


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Explain schematic

FLUIDSAMPLING

PORT

PILOTPUMP

PILOTRELIEFVALVE

PILOTFILTER

VARIABLE IMPLEMENT PUMPLESS THAN 28940 kPa (4200 psi)ENGINE SPEED MORE THAN 1400 rpm

VARIABLE IMPLEMENT PUMPSOLENOID VALVE

LARGEACTUATOR

SMALLACTUATOR

TO TANK

TO IMPLEMENTCONTROL VALVE

TO PILOTSYSTEM

PUMP

LOADLIMIT

CONTROL

PRESSURECUTOFF

BYPASSSWITCH

VARIABLE IMPLEMENT PUMPCONTROL VALVE

Variable Implement Pump Control Schematics

This schematic shows the oil flow in the variable implement pump control

valve when the system pressure is less than 28940 kPa (4200 psi) and the

engine speed is more than 1400 rpm.

The pilot pump pulls oil from the tank and sends oil flow through the pilotfilter to the pilot system. The pilot relief valve limits the pilot system oil

pressure to 2400 205 kPa (350 30 psi). When the key start switch is in

the ON position, the variable pump solenoid valve is activated. Pilot oil

flows through the variable implement pump solenoid valve to the load limit

control. The combined force of the system oil and the small actuator

spring holds the variable implement pump swashplate at maximum angle.


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Explain schematic

FLUIDSAMPLING

PORT

PILOTPUMP

PILOTRELIEFVALVE

PILOTFILTER

VARIABLE IMPLEMENT PUMPMORE THAN 28940 kPa (4200 psi)ENGINE SPEED MORE THAN 1400 rpm


LARGEACTUATOR

SMALLACTUATOR

TO TANK


TO PILOTSYSTEM

PUMP

LOADLIMIT

CONTROL

PRESSURECUTOFF

BYPASSSWITCH


When the system pressure increases to 28940 kPa (4200 psi) and the

engine speed is more than 1400 rpm, the variable implement pump oil

becomes signal oil for the variable implement pump control valve. The

signal pressure moves the pressure cutoff valve against the spring. The

signal oil at the bottom of the pressure cutoff valve flows past the pressure

cutoff valve to the large actuator piston and destrokes the pump. The

variable pump pressure will not exceed 28940 kPa (4200 psi).


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Explain schematic

FLUIDSAMPLING

PORT

PILOTPUMP

PILOTRELIEFVALVE

PILOTFILTER

VARIABLE IMPLEMENT PUMPLESS THAN 11590 kPa (1700 psi)ENGINE SPEED LESS THAN 1400 rpm


LARGEACTUATOR

SMALLACTUATOR

TO TANK


TO PILOTSYSTEM

PUMP

LOADLIMIT

CONTROL

PRESSURECUTOFF

BYPASSSWITCH VARIABLE IMPLEMENT PUMP

CONTROL VALVE

When the system pressure is less than 11590 kPa (1700 psi) and the engine

speed is less than 1400 rpm, the variable implement pump solenoid valve

begins to modulate the pressure to the load limit control. Below 11590 kPa

(1700 psi) system pressure is not adequate to destroke the pump, and the

pump continues to deliver full flow.


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Explain schematic

FLUIDSAMPLING

PORT

PILOTPUMP

PILOTRELIEFVALVE

PILOTFILTER

VARIABLE IMPLEMENT PUMPMORE THAN 11590 kPa (1700 psi)LESS THAN 28940 kPa (4200 psi)

ENGINE SPEED LESS THAN 1400 rpm


LARGEACTUATOR

SMALLACTUATOR

TO TANK


TO PILOTSYSTEM

PUMP

LOADLIMIT

CONTROL

PRESSURECUTOFF

BYPASSSWITCH


When system pressure is between 11590 kPa (1700 psi) and 28940 kPa

(4200 psi) and the engine speed is less than 1400 rpm, the variable

implement pump solenoid valve modulates the pressure of the pilot oil to

the load limit control cylinder. The signal oil acting on the vertical piston

in the small actuator assembly moves the pivot lever on the load limit

control. The pivot lever moves the load limit control valve against the

spring and load limit control cylinder pressure. The oil at the bottom of

the load limit control valve flows through the load limit control valve and

through the pressure cutoff valve to the large actuator piston. The large

actuator piston reduces the angle of the swashplate and limits the load on

the engine to approximately 40%.


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Explain schematic

FLUIDSAMPLING

PORT

PILOTPUMP

PILOTRELIEFVALVE

PILOTFILTER

VARIABLE IMPLEMENT PUMPMORE THAN 28940 kPa (4200 psi)ENGINE SPEED LESS THAN 1400 rpm


LARGEACTUATOR

SMALLACTUATOR

TO TANK


TO PILOTSYSTEM

PUMP

LOADLIMIT

CONTROL

PRESSURECUTOFF

BYPASSSWITCH VARIABLE IMPLEMENT PUMP

CONTROL VALVE

When the system pressure reaches 28940 kPa (4200 psi) and the engine

speed is less than 1400 rpm, the variable implement pump solenoid valve

modulates the pressure of the pilot oil to the load limit control cylinder.

The load limit control attempts to destroke the pump to 40% load.

However, because the system pressure is at high pressure cutoff, signal oil

acting on the end of the pressure cutoff valve shifts the valve. Signal oil

from the load limit control is blocked and the signal oil from the pressure

cutoff valve flows to the large actuator and destrokes the pump.


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Explain the implement

control valve operation

LIFTSPOOL

RAISEPILOT CONTROL

ACTUATOR

LOWERPILOT CONTROL

ACTUATOR

LOADCHECKVALVE

PASSAGE TONEXT VALVE

SUPPLYPASSAGE

TOTANK

RODEND

HEADEND

PILOTPASSAGE

TOTANK

LINE RELIEFMAKEUPVALVE


RAISEACTUATORSOLENOID

LOWERACTUATORSOLENOID

INTERNALPASSAGE

IMPLEMENT CONTROL VALVEHOLD

Implement Control Valve Operation

In the HOLD position, pilot oil pressure is present at both ends of the

control valve lift spool. The pilot oil and the centering springs keep the

lift spool in the centered position. The control valve lift spool blocks oil

flow to the lift cylinders, and oil from the lift cylinders is blocked by the

lift spool. The oil is trapped and the cylinders will remain in the HOLD

position.

Oil from the fixed implement pump enters the supply passage, flows

around the lift spool, and flows to the tank. The flow of oil through the

lift control valve for the variable implement pump is the same as the flow

of oil through the lift control valve for the fixed implement pump.

The flow of oil through the tilt control valve is similar to the flow of oil

through the lift control valve. However, the tilt control valve has priorityover the lift control valve.


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Explain the implement

control valve operation

LIFTSPOOL


LOWERPILOT CONTROL

ACTUATOR

LOAD CHECKVALVE

TOTANK

RODEND

HEADEND

PILOTPASSAGE

INTERNALPASSAGE

TOTANK


PASSAGE TONEXT VALVE

SUPPLYPASSAGE

RAISEACTUATORSOLENOID

RAISEPILOT CONTROL

ACTUATOR

LOWERACTUATORSOLENOID

IMPLEMENT CONTROL VALVELOWER

When the operator moves the implement control valve to the LOWER

position, the lift lever sensor sends a PWM signal to the Implement ECM.

Then the Implement ECM sends a proportional signal that energizes the

lower actuator solenoid.

The solenoid moves the spool for the pilot control actuator and the pilot

oil at the right end of the lift spool is drained to the tank. The pilot oil

pressure on the left end of the lift spool moves the lift spool to the

LOWER position.

The lift spool directs oil from the implement pump to the load check

valve. Oil flows through the load check valve and through the lift spool to

the rod end of the lift cylinders. The lift spool also opens the tank

passages to allow the oil from the head end of the lift cylinders to return to

the tank.

The tilt control valve is similar to the lift control valve. The variable

implement control valves are similar to the fixed implement control

valves.


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Objective 6

Visuals 42 - 46

Explain schematic

LIFTLEVER

SENSOR

FIXEDPUMP

VARIABLEPUMP

SOLENOIDVALVE

VARIABLEPUMP

LEFTLIFT

CYLINDER

RIGHTLIFT

CYLINDER

TILTCYLINDER

SHUTTLEVALVE

PRESSUREREDUCING

VALVE

PILOTON/OFFVALVE

CHECKVALVE

BUCKETKICKOUTDETENT

SOLENOID



SWITCH



RAISEKICKOUTDETENT

SOLENOID

LOWERKICKOUTDETENT

SOLENOID

CATDATALINK

ELECTRO-HYDRAULIC

IMPLEMENT SYSTEM

RELIEFVALVE

PILOTRELIEF VALVE

PILOTPUMP

RELIEFVALVE

HOLD

BYPASSSWITCH

BYPASSSWITCH

BYPASSSWITCH

MANUAL

LOWER

VALVE

TILTLEVER

SENSOR

ELECTRONICCONTROLMODULE

IMPLEMENTCONTROL

VALVE

IMPLEMENTCONTROL

VALVE

HYDRAULICACTUATOR

Electro-Hydraulic Implement System Schematics

When the implement lockout switch is in the ON position, the Implement

ECM energizes the pilot on/off solenoid. The pilot on/off solenoid opens

the pilot on/off valve.

The pilot pump pulls oil from the hydraulic tank and sends oil flow

through the pilot on/off valve to the hydraulic actuators at each end of the

control valve spools. Pilot oil pressure increases to the relief valve

pressure setting. The relief valve opens and maintains a constant pressure

in the pilot system of 2400 kPa (350 psi). The control valve spools are

hydraulically locked in the HOLD position.

In the HOLD position, the control valve spools block oil flow to the lift

and tilt cylinders. Oil from the fixed pump and the variable pump flows

past the respective control valve spools to the tank.


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Slow tilt back uses

fixed pump only

LIFTLEVER

SENSOR

FIXEDPUMP

VARIABLEPUMP

SOLENOIDVALVE

VARIABLEPUMP

LEFTLIFT

CYLINDER

RIGHTLIFT

CYLINDER

TILTCYLINDER

SHUTTLEVALVE

PRESSUREREDUCING

VALVE

PILOTON/OFFVALVE

CHECKVALVE

BUCKETKICKOUTDETENT

SOLENOID



SWITCH



RAISEKICKOUTDETENT

SOLENOID

LOWERKICKOUTDETENT

SOLENOID

CATDATALINK

ELECTRO-HYDRAULIC

IMPLEMENT SYSTEM

RELIEFVALVE

PILOTRELIEF VALVE

PILOTPUMP

RELIEFVALVE

SLOW TILT BACK

IMPLEMENTCONTROL

VALVE

IMPLEMENTCONTROL


TILTLEVER

SENSOR

MANUAL

LOWER

VALVE

BYPASSSWITCH

BYPASSSWITCH

BYPASSSWITCH

HYDRAULICACTUATOR

When the tilt lever is moved to the SLOW TILT BACK position, the tilt

lever sensor sends a PWM signal to the Implement ECM. The Implement

ECM analyzes the input signals from the tilt lever sensor, the lift linkage

position sensor, and the tilt linkage position sensor. The Implement ECM

then sends a proportional signal to ENERGIZE the tilt back hydraulic

actuator solenoid on the fixed pump implement control valve. The tilt

back solenoid moves the hydraulic actuator valve and sends pilot oil at the

tilt back end of the tilt/dump control valve spool to drain. This condition

reduces the oil pressure at the tilt back end of the tilt/dump control valve

spool. The oil pressure on the dump end of the tilt/dump control valve

spool moves the valve spool to the TILT BACK position.


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Variable pump oil is

not needed for slow

implement operation

The fixed pump oil flows past the tilt/dump control valve spool to the rod

end of the tilt cylinder. Tilt cylinder head end oil flows past the tilt/dump

control valve spool to the tank.

The variable pump oil is not needed for SLOW TILT BACK operation.

The Implement ECM does not energize the variable pump tilt back

hydraulic actuator solenoid. The variable pump oil flows through the

variable pump implement control valve to the tank.

With the exception of the FLOAT position, the Implement ECM uses the

oil from the fixed pump for all implement operations until the operational

demand for oil is greater than the fixed pump can supply. The Implement

ECM will then use oil from the variable pump to satisfy the demand.


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Both pumps used

during fast implement

operation

LIFTLEVER

SENSOR

FIXEDPUMP

VARIABLEPUMP

SOLENOIDVALVE

VARIABLEPUMP

LEFTLIFT

CYLINDER

RIGHTLIFT

CYLINDER

TILTCYLINDER

SHUTTLEVALVE

PRESSUREREDUCING

VALVE

PILOTON/OFFVALVE

CHECKVALVE

BUCKETKICKOUTDETENT

SOLENOID



SWITCH



RAISEKICKOUTDETENT

SOLENOID

LOWERKICKOUTDETENT

SOLENOID

CATDATALINK

ELECTRO-HYDRAULIC

IMPLEMENT SYSTEM

RELIEFVALVE

PILOTRELIEF VALVE

PILOTPUMP

RELIEFVALVE

FAST TILT BACK

IMPLEMENTCONTROL

VALVE

IMPLEMENTCONTROL


TILTLEVER

SENSOR

MANUAL

LOWER

VALVE

BYPASSSWITCH

BYPASSSWITCH

BYPASSSWITCH

HYDRAULICACTUATOR

When the tilt lever is moved to the FAST TILT BACK position, the tilt

lever sensor sends a PWM signal to the Implement ECM. The Implement

ECM analyzes the input signals from the tilt lever sensor, the lift linkage

position sensor, and the tilt linkage position sensor. The Implement ECM

sends a signal to ENERGIZE the tilt back hydraulic actuator solenoid on

the fixed pump implement control valve and a signal to ENERGIZE the

tilt back hydraulic actuator solenoid on the variable pump implement

control valve. The signals may be of different values. Each solenoid

moves the respective hydraulic actuator valve and sends pilot oil at the tilt

back end of the respective tilt/dump control valve spool to drain. This

condition reduces the pilot oil pressure at the tilt back end of the control

valve spool. The oil pressure on the dump end of the respective tilt/dump

control valve spool moves the control valve spool to the TILT BACK

position.


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The fixed pump oil flows around the tilt/dump control valve spool in the

fixed pump implement control valve to the rod end of the tilt cylinder.

The variable pump oil flows around the tilt/dump control valve spool inthe variable pump implement control valve to the rod end of the tilt

cylinder. The tilt cylinder head end oil flows past both tilt/dump control

valve spools to the tank. The return oil flow past each valve spool is

proportional to the supply oil flow past the valve spool.

The desired tilt cylinder speed determines the difference in oil flow

between the fixed pump and the variable pump. A slow tilt cylinder

speed will cause a larger difference in oil flow between the two pumps

than a fast tilt cylinder speed.


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Slow lift uses fixed

pump only

LIFTLEVER

SENSOR

FIXEDPUMP

VARIABLEPUMP

SOLENOIDVALVE

VARIABLEPUMP

LEFTLIFT

CYLINDER

RIGHTLIFT

CYLINDER

TILTCYLINDER

SHUTTLEVALVE

PRESSURER

SERV2633 - - Monitor & Implement - Text - 992G

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Transcript of SERV2633 - - Monitor & Implement - Text - 992G