Hitachi ZW370 User manual

TO97C5-E-02ZW370 WHEEL LOADER TECHNICAL MANUAL OPERATIONAL PRINCIPLE
PRINTED IN JAPAN (E) 2018, 03
Service Manual consists of the following separate Part No.
Technical Manual (Operational Principle) : Vol. No.TO97C5-E
Technical Manual (Troubleshooting) : Vol. No.TT97C5-E
Workshop Manual : Vol. No.W97C5-E
TO97C5-E-02
PART NO.
Wheel Loader
Technical Manual
Operational Principle
URL:http://www.hitachi-c-m.com
ZW370

Find manuals at https://best-manuals.com

October 2016
Foreword
To ensure good machine performance, reduce failures or problems, and prolong the service life of each component,
it is necessary to operate the machine as is directed in the Operator and Maintenance Manual.
To effectively diagnose and repair the machine, it is important to follow the guidelines laid out in this Shop Manual.
General Information
Function and structure
For the engine, refer to the engine Shop Manual provided by the engine manufacturer.
The purpose of this manual is to provide information on the product and the correct maintenance and repair meth-
ods. Please read this manual to ensure correct troubleshooting and good repair service.
This manual will be periodically reviewed and revised for more satisfactory content. If you have any opinion or
requests, please inform us.
Find manuals at https://best-manuals.com

Safety Symbols
An accident may occur if you disregard safety rules.
In this manual, several expressions are used according to levels of danger for inspection and repair work as shown
below. Read the work procedures and cautions described in this manual, and take preventive measures against
possible problems before starting service work.
We cannot predict all possible accidents or incidents that may occur during service work. Therefore, an accident that
is not specifically mentioned in this manual may occur. To protect yourself from all accidents, be careful when doing
service work.
DANGER
This danger symbol identifies special warnings or
procedures which, if not strictly observed, will result
in death or serious injury.
WARNING
This warning symbol identifies special warnings or
procedures which, if not strictly observed, could result
in death or serious injury.
CAUTION
This caution symbol identifies special instructions or
procedures which, if not strictly observed, may result
in minor or moderate injury.
IMPORTANT
This important symbol identifies special instructions
or procedures which, if not correctly followed, may
result in serious machine damage.
Find manuals at https://best-manuals.com

CONTENTS
00 General Information ......................................................................................................................................... 00-1
How to Use Manual ........................................................................................................................................... 00-2
Safety precautions ...................................................................................................................................... 00-2
Symbols ...................................................................................................................................................... 00-3
Outline ............................................................................................................................................................... 00-4
Layout of main components ........................................................................................................................ 00-4
Inspection and maintenance table .............................................................................................................. 00-6
Recommended lubricants ........................................................................................................................... 00-9
Coolant ..................................................................................................................................................... 00-10
Lubrication chart ........................................................................................................................................00-11
Weight of main components ..................................................................................................................... 00-12
Bolt tightening torque ................................................................................................................................ 00-13
Hose band tightening torque ..................................................................................................................... 00-17
Liquid gasket and screw lock agent .......................................................................................................... 00-18
Cautions regarding welding repair service ................................................................................................ 00-20
03 Measurement for Performance Check ............................................................................................................. 03-1
Cautions on Safety ............................................................................................................................................ 03-2
Standard Measurement Values for Performance Check ................................................................................... 03-3
12 Function & Structure Chassis Group ................................................................................................................ 12-1
Front Chassis .................................................................................................................................................... 12-2
Loading linkage ........................................................................................................................................... 12-2
Loading linkage pin ..................................................................................................................................... 12-4
Rear Chassis .................................................................................................................................................... 12-5
Fuel tank ..................................................................................................................................................... 12-5
Floor board mount ....................................................................................................................................... 12-6
Center Pin ......................................................................................................................................................... 12-7
Upper center pin ......................................................................................................................................... 12-7
Lower center pin ......................................................................................................................................... 12-7
Dust seal ..................................................................................................................................................... 12-8
13 Check & Adjustment Chassis Group ................................................................................................................ 13-1
Linkage Pin ....................................................................................................................................................... 13-2
Liner ............................................................................................................................................................ 13-2
Find manuals at https://best-manuals.com

Center Pin .........................................................................................................................................................13-5
Adjusting shim .............................................................................................................................................13-5
Grease nipple installation direction .............................................................................................................13-5
Installing bearing outer ring .........................................................................................................................13-5
22 Function & Structure Power Group ..................................................................................................................22-1
Power Line ........................................................................................................................................................22-2
Engine / Transmission .......................................................................................................................................22-4
Engine / transmission mount .......................................................................................................................22-4
Radiator (S/N 9001~9150) ................................................................................................................................22-5
Radiator (S/N 9151~) ........................................................................................................................................22-6
Propeller Shaft ..................................................................................................................................................22-8
Second propeller shaft assembly ................................................................................................................22-9
Third propeller shaft assembly ..................................................................................................................22-10
Axle Assembly ................................................................................................................................................. 22-11
Axle Support ....................................................................................................................................................22-12
Torque Proportioning Type Differential Gear (TPD) ........................................................................................22-14
Function of T.P.D .......................................................................................................................................22-17
Operation of T.P.D .....................................................................................................................................22-18
Limited Slip Differential (LSD) (option) ............................................................................................................22-19
LSD structure ............................................................................................................................................22-19
LSD function ..............................................................................................................................................22-23
LSD operation ...........................................................................................................................................22-23
23 Check & Adjustment Power Group ...................................................................................................................23-1
Engine ...............................................................................................................................................................23-2
Measuring engine speed .............................................................................................................................23-2
Measuring engine oil pressure ....................................................................................................................23-2
Propeller Shaft ..................................................................................................................................................23-3
Propeller shaft phase ..................................................................................................................................23-3
Second propeller shaft alignment ................................................................................................................23-3
Propeller shaft tightening torque .................................................................................................................23-4
Axle ...................................................................................................................................................................23-5
Axle nut tightening procedure .....................................................................................................................23-5
Differential gear adjustment procedure .......................................................................................................23-6
Find manuals at https://best-manuals.com

32 Function & Structure Torque Converter and Transmission Group ................................................................... 32-1
Torque Converter .............................................................................................................................................. 32-2
Torque converter structure .......................................................................................................................... 32-2
Power flow path .......................................................................................................................................... 32-2
Torque multiplication ................................................................................................................................... 32-2
Torque Converter (Lock-up) (Option) ................................................................................................................ 32-3
Lock-up clutch structure .............................................................................................................................. 32-4
Lock-up clutch function (only forward) ........................................................................................................ 32-4
Torque Converter Gear Pump ........................................................................................................................... 32-6
Gear pump specifications ........................................................................................................................... 32-6
Gear pump specifications ........................................................................................................................... 32-7
Transmission ..................................................................................................................................................... 32-8
Clutch combination ..................................................................................................................................... 32-8
Planetary gear ............................................................................................................................................. 32-8
Shift lever position ....................................................................................................................................... 32-8
Downshift button operation ......................................................................................................................... 32-8
Gear train and number of teeth ................................................................................................................... 32-9
Clutch Pack ..................................................................................................................................................... 32-12
Power Flow Path in the Transmission ............................................................................................................. 32-13
Forward 1st speed power flow path .......................................................................................................... 32-13
Forward 2nd speed power flow path ......................................................................................................... 32-14
Forward 3rd speed power flow path .......................................................................................................... 32-14
Forward 4th speed power flow path .......................................................................................................... 32-15
Reverse 1st speed power flow path .......................................................................................................... 32-16
Reverse 2nd speed power flow path ......................................................................................................... 32-16
Reverse 3rd speed power flow path ......................................................................................................... 32-17
Hydraulic System Diagram ............................................................................................................................. 32-18
Hydraulic Circuit Diagram ............................................................................................................................... 32-20
Oil Flow ........................................................................................................................................................... 32-22
Oil flow in the torque converter line ........................................................................................................... 32-22
Oil flow to the clutch .................................................................................................................................. 32-22
T/C and T/M Oil Circulation ............................................................................................................................. 32-23
Find manuals at https://best-manuals.com

Modulator Valve Unit .......................................................................................................................................32-25
Interior schematic (simple explanation) .....................................................................................................32-27
Modulator valve function ...........................................................................................................................32-28
Modulator valve operation .........................................................................................................................32-30
Control Valve Assembly ..................................................................................................................................32-32
Check valve ...............................................................................................................................................32-34
Clutch solenoid valve assembly ................................................................................................................32-35
Clutch valve assembly ..............................................................................................................................32-39
33 Check & Adjustment Torque Converter and Transmission Group ...................................................................33-1
Clutch Oil Pressure and Time Lag ....................................................................................................................33-2
Measuring clutch oil pressure .....................................................................................................................33-2
Measuring clutch time lag ...........................................................................................................................33-4
42 Function & Structure Hydraulic Group ..............................................................................................................42-1
Flushing Hydraulic Circuit .................................................................................................................................42-2
Purpose of flushing .....................................................................................................................................42-2
Cautions on Hydraulic Parts Replacement .......................................................................................................42-3
Hydraulic Circuit Symbols .................................................................................................................................42-4
Hydraulic lines .............................................................................................................................................42-4
Pumps & motors ..........................................................................................................................................42-4
Cylinders .....................................................................................................................................................42-4
Operation methods ......................................................................................................................................42-5
Pressure control valve .................................................................................................................................42-5
Flow control valve .......................................................................................................................................42-5
Directional control valve ..............................................................................................................................42-6
Check valve .................................................................................................................................................42-6
Miscellaneous hydraulic symbols ................................................................................................................42-7
Hydraulic System Operation .............................................................................................................................42-8
Hydraulic system operation outline .............................................................................................................42-8
Layout of Hydraulic Units ................................................................................................................................42-10
Hydraulic Tank ................................................................................................................................................. 42-11
Hydraulic Tank (S/N 9001~9300) .............................................................................................................. 42-11
Hydraulic Tank (S/N 9301~) ......................................................................................................................42-13
Hydraulic tank specifications .....................................................................................................................42-15
Hydraulic oil level check ............................................................................................................................42-16
Find manuals at https://best-manuals.com

Hydraulic Pump ............................................................................................................................................... 42-17
Loading and pilot and brake pump/Steering pump ................................................................................... 42-17
Loading and pilot and brake pump/Steering pump specifications ............................................................. 42-17
Hydraulic pump principle ........................................................................................................................... 42-18
Hydraulic pump wear plate ....................................................................................................................... 42-19
Hydraulic pump bushing lubrication .......................................................................................................... 42-19
Hydraulic Cylinder ........................................................................................................................................... 42-20
Boom cylinder ........................................................................................................................................... 42-20
Bucket cylinder .......................................................................................................................................... 42-20
Steering cylinder ....................................................................................................................................... 42-21
Hydraulic cylinder specifications ............................................................................................................... 42-22
Loading System .............................................................................................................................................. 42-23
Reducing Valve (for Pilot Pressure) ................................................................................................................ 42-24
Pilot valve (S/N 9001~9250) ........................................................................................................................... 42-25
Pilot valve (S/N 9251~9255) ........................................................................................................................... 42-30
Pilot valve (S/N 9256~) ................................................................................................................................... 42-35
Multiple Control Valve (KML35A/2T003B) ....................................................................................................... 42-40
Multiple control valve specifications .......................................................................................................... 42-41
Multiple control valve main relief valve ..................................................................................................... 42-42
Multiple control valve overload relief valve (with make-up function) ......................................................... 42-44
Multiple control valve make-up valve ........................................................................................................ 42-45
Multiple control valve bucket spool ........................................................................................................... 42-46
Multiple control valve boom spool ............................................................................................................. 42-48
Adapter (Orifice) .............................................................................................................................................. 42-51
Ride Control (OPT) ......................................................................................................................................... 42-52
Ride control hydraulic circuit ..................................................................................................................... 42-52
Ride control operation ............................................................................................................................... 42-53
Ride control valve assembly (Reducing valve circuit) ............................................................................... 42-55
Ride control valve assembly (Accumulator circuit) ................................................................................... 42-58
Accumulator (for ride control) .................................................................................................................... 42-61
Steering System .............................................................................................................................................. 42-62
Find manuals at https://best-manuals.com

Orbitrol®...........................................................................................................................................................42-63
Orbitrol®structure .....................................................................................................................................42-63
Orbitrol®specifications ..............................................................................................................................42-64
Orbitrol®operation ....................................................................................................................................42-65
Orbitrol®feed-back mechanism operation ................................................................................................42-67
Steering speed and flow rate control .........................................................................................................42-68
Hydraulic pump oil amount and steering force ..........................................................................................42-68
Orbit rotor operation principle ....................................................................................................................42-69
Steering Valve (KVS32-A4.0/20) .....................................................................................................................42-70
Steering valve operation ...........................................................................................................................42-72
Steering spool variable throttle ..................................................................................................................42-74
Steering valve flow control spool ...............................................................................................................42-75
Steering valve main relief valve ................................................................................................................42-76
Steering valve overload relief valve ..........................................................................................................42-78
Steering pilot circuit and its operation .......................................................................................................42-80
Stop Valve .......................................................................................................................................................42-82
Stop valve function ....................................................................................................................................42-83
Stop valve operation .................................................................................................................................42-83
Reducing Valve (for Orbitrol®) .........................................................................................................................42-84
Steering Line Filter ..........................................................................................................................................42-85
K-Lever (OPT) .................................................................................................................................................42-86
Hydraulic circuit .........................................................................................................................................42-86
Hydraulic line diagram ...............................................................................................................................42-87
Hydraulic line .............................................................................................................................................42-88
Solenoid valve mount ................................................................................................................................42-89
Solenoid valve assembly (1/2) ..................................................................................................................42-90
Solenoid valve assembly (2/2) ..................................................................................................................42-91
Efficient Loading System .................................................................................................................................42-92
Efficient loading system outline .................................................................................................................42-92
Mounting of the ELS valve ........................................................................................................................42-93
Mounting of the variable kickout sensor ....................................................................................................42-94
Efficient loading system operation ............................................................................................................42-95
Fan Motor System ...........................................................................................................................................42-96
Mounting of fan motor ...............................................................................................................................42-96
Find manuals at https://best-manuals.com

Fan Motor Line ................................................................................................................................................ 42-97
Hydraulic circuit (fan motor normal rotation) ............................................................................................. 42-99
Proportional relief valve (S/N 9001~9150) .............................................................................................. 42-101
Proportional relief valve (S/N 9151~) ...................................................................................................... 42-103
Fan motor ................................................................................................................................................ 42-105
Reversing Fan Motor Line (OPT) .................................................................................................................. 42-108
Reversing fan motor function .................................................................................................................. 42-108
Hydraulic circuit (Reverse rotation) ..........................................................................................................42-112
Secondary Steering ........................................................................................................................................42-113
Secondary steering operation ..................................................................................................................42-113
Secondary steering motor and pump .......................................................................................................42-115
43 Check & Adjustment Hydraulic Group .............................................................................................................. 43-1
Loading/Steering Circuit Relief Valve/Ride Control Circuit Reducing Valve (OPT) ........................................... 43-2
Loading circuit relief valve setting pressures .............................................................................................. 43-2
Ride control circuit reducing valve setting pressures (OPT) ....................................................................... 43-7
Steering circuit relief valve setting pressures .............................................................................................. 43-9
Hydraulic Cylinder ........................................................................................................................................... 43-14
Cylinder natural drift .................................................................................................................................. 43-14
Stop Valve ....................................................................................................................................................... 43-17
Stop valve adjustment procedure ............................................................................................................. 43-17
52 Function & Structure Brake Group ................................................................................................................... 52-1
Brake System Outline ....................................................................................................................................... 52-2
Service brake .............................................................................................................................................. 52-2
Parking brake .............................................................................................................................................. 52-2
Adjustment of axle internal pressure ........................................................................................................... 52-2
Brake Units Layout ............................................................................................................................................ 52-3
Unloader Valve .................................................................................................................................................. 52-4
Unloader valve operation ............................................................................................................................ 52-6
Valve Unit .......................................................................................................................................................... 52-7
Accumulator ...................................................................................................................................................... 52-9
Brake Valve ..................................................................................................................................................... 52-10
Brake valve performance chart ..................................................................................................................52-11
Brake valve outline .................................................................................................................................... 52-12

Service Brake ..................................................................................................................................................52-14
Service brake operation ............................................................................................................................52-14
Service brake friction plate ........................................................................................................................52-15
Service brake steel plate ...........................................................................................................................52-16
Service brake piston ..................................................................................................................................52-17
Service brake pedal stroke adjusting mechanism (S/N 9001~9014) ........................................................52-18
Brake circuit air bleeding procedure ..........................................................................................................52-20
Parking Brake ..................................................................................................................................................52-22
Parking brake operation ............................................................................................................................52-25
Parking brake friction plate ........................................................................................................................52-27
Parking brake steel plate ...........................................................................................................................52-27
Parking brake solenoid valve ....................................................................................................................52-28
Parking Brake Manual Release .......................................................................................................................52-29
Brake Circuit Check Valve ...............................................................................................................................52-31
Auto Brake ......................................................................................................................................................52-32
Auto brake circuit ......................................................................................................................................52-32
Auto brake operation set value .................................................................................................................52-32
Solenoid valve (for Autobrake circuit) .......................................................................................................52-33
Pressure Sensor (for stop lamp and declutch) ................................................................................................52-34
Pressure sensor (for declutch) ..................................................................................................................52-34
Pressure sensor (for stop lamp) ................................................................................................................52-34
53 Check & Adjustment Brake Group ...................................................................................................................53-1
Brake Circuit Oil Pressure .................................................................................................................................53-2
Unloader valve setting pressure ..................................................................................................................53-2
Brake valve oil pressure ..............................................................................................................................53-4
Service Brake ....................................................................................................................................................53-6
Service brake performance check ...............................................................................................................53-6
Service brake friction plate wear measurement ..........................................................................................53-7
Cautions on installing brake discs ...............................................................................................................53-9
Parking Brake ..................................................................................................................................................53-10
Parking brake performance check ............................................................................................................53-10
62 Function & Structure Electrical Group ..............................................................................................................62-1
How to Use Electrical Wiring Diagram ..............................................................................................................62-2
Utilisation des schémas des câblages électriques (FRANÇAIS) ......................................................................62-3
Verwendung des elektrischen Schaltplans (DEUTSCH) ...................................................................................62-4

Modalità di utilizzo dello schema dei collegamenti elettrici (ITALIANO) ............................................................ 62-5
Cómo utilizar un Diagrama de Alambrado Eléctrico (ESPAÑOL) .....................................................................62-6
Como Utilizar o Diagrama de Ligações Eléctricas (PORTUGUÊS) .................................................................. 62-7
Electrical Cable Color Codes ............................................................................................................................ 62-8
Electrical Circuit Symbols ................................................................................................................................. 62-9
Sensor Mount .................................................................................................................................................. 62-10
Fuse .................................................................................................................................................................62-11
Fuse box ....................................................................................................................................................62-11
Fusible link ................................................................................................................................................ 62-13
Engine Start Circuit ......................................................................................................................................... 62-14
Engine start circuit diagram ...................................................................................................................... 62-14
Neutral starter ........................................................................................................................................... 62-15
Starter switch ............................................................................................................................................ 62-16
Battery relay .............................................................................................................................................. 62-17
Alternator I terminal wire ........................................................................................................................... 62-18
Diode unit .................................................................................................................................................. 62-18
Neutral relay .............................................................................................................................................. 62-19
Magnetic switch ........................................................................................................................................ 62-20
Voltage relay ............................................................................................................................................. 62-21
Power Generating/Charging Circuit ................................................................................................................ 62-22
Alternator .................................................................................................................................................. 62-22
ECM (Engine Controller) ................................................................................................................................. 62-23
Function of ECM ....................................................................................................................................... 62-23
Connection diagram .................................................................................................................................. 62-23
Monitor lamp test ...................................................................................................................................... 62-24
Failure diagnosis ....................................................................................................................................... 62-25
Quantum fault code information ................................................................................................................ 62-28
Accelerator pedal ...................................................................................................................................... 62-34

Transmission Control Circuit and Monitor Circuit ............................................................................................62-37
Machine control unit (MCU) ......................................................................................................................62-37
Machine control unit (MCU) connection diagram (S/N 9001~9350) .........................................................62-39
Machine control unit (MCU) connection diagram (S/N 9351~) .................................................................62-41
Machine control unit (MCU) function .........................................................................................................62-43
Adjustable declutch preset switch .............................................................................................................62-52
Monitoring system .....................................................................................................................................62-62
Operation monitor lamps ...........................................................................................................................62-64
Instrument Panel and Switch ..........................................................................................................................62-65
Instrument panel (S/N 9001~9350) ...........................................................................................................62-65
Instrument panel (S/N 9351~) ...................................................................................................................62-66
Instrument panel rear surface ...................................................................................................................62-67
Gauge circuit .............................................................................................................................................62-69
Fuel gauge circuit ......................................................................................................................................62-71
MODM .............................................................................................................................................................62-72
MODM function .........................................................................................................................................62-72
Monitor Changeover ..................................................................................................................................62-72
Information Monitor ...................................................................................................................................62-75
Replacement Monitor ................................................................................................................................62-79
Fault Log Monitor ......................................................................................................................................62-85
Input/Output Monitor .................................................................................................................................62-92
Parameter Setting Monitor ........................................................................................................................62-96
Specification Setting Monitor ...................................................................................................................62-105
Electrical Detent Circuit ..................................................................................................................................62-111
Bucket leveler ...........................................................................................................................................62-111
Detent solenoid ....................................................................................................................................... 62-112
Lift kickout & lower kickout ...................................................................................................................... 62-113
Sensor assy ............................................................................................................................................ 62-115
Detent solenoid ....................................................................................................................................... 62-117
Preset height adjustment ........................................................................................................................ 62-117
Diode ............................................................................................................................................................. 62-118
Diode check method ............................................................................................................................... 62-119
Caution for diode check method ............................................................................................................. 62-119
Surge voltage and surge suppression diodes .........................................................................................62-121

72 Function & Structure Operator Station Group .................................................................................................. 72-1
Cabin ................................................................................................................................................................. 72-2
Glass ........................................................................................................................................................... 72-3
Wiper mount ................................................................................................................................................ 72-6
Wiper motor ................................................................................................................................................ 72-7
Operator Seat ................................................................................................................................................... 72-9
Steering and Transmission Shift Lever ........................................................................................................... 72-10
Tilt case ......................................................................................................................................................72-11
Column shaft ............................................................................................................................................. 72-12
Shift lever .................................................................................................................................................. 72-12
Air Conditioner ................................................................................................................................................ 72-13
Denso air conditioner components ........................................................................................................... 72-13
Denso air conditioner structure ................................................................................................................. 72-14
Function of cooling mechanism ................................................................................................................ 72-19
Cooling circuit ........................................................................................................................................... 72-22
Electrical circuit ......................................................................................................................................... 72-23
Air conditioner functions of components ................................................................................................... 72-24
Charge of refrigerant ................................................................................................................................. 72-52
Air conditioner troubleshooting ................................................................................................................. 72-69
73 Check & Adjustment Operator Station Group .................................................................................................. 73-1
Air Conditioner .................................................................................................................................................. 73-2
Adjustment of lubricating oil quantity when components of air conditioner are replaced ............................ 73-2
Adjustment of air gap (between hub and rotor) in compressor magnetic clutch ......................................... 73-5
Compressor V-belt adjustment .................................................................................................................... 73-6
Parts to be replaced periodically ................................................................................................................. 73-7
92 Drawing & Diagrams ........................................................................................................................................ 92-1
Axle Assembly .................................................................................................................................................. 92-2
Torque Converter and Transmission ................................................................................................................. 92-3
Hydraulic & Brake Circuit (S/N 9001~9250) ...................................................................................................... 92-4
Hydraulic & Brake Circuit (S/N 9251~) .............................................................................................................. 92-5
Brake Circuit ..................................................................................................................................................... 92-6
Electrical Wiring Diagram (1/3) (S/N 9001~9048) ............................................................................................. 92-7
Electrical Wiring Diagram (2/3) (S/N 9001~9048) ............................................................................................. 92-8
Electrical Wiring Diagram (3/3) (S/N 9001~9048) ............................................................................................. 92-9
Electrical Wiring Diagram (1/3) (S/N 9049~9250) ........................................................................................... 92-10

Electrical Wiring Diagram (2/3) (S/N 9049~9250) ........................................................................................... 92-11
Electrical Wiring Diagram (3/3) (S/N 9049~9250) ...........................................................................................92-12
Electrical Wiring Diagram (1/3) (S/N 9251~9350) ...........................................................................................92-13
Electrical Wiring Diagram (2/3) (S/N 9251~9350) ...........................................................................................92-14
Electrical Wiring Diagram (3/3) (S/N 9251~9350) ...........................................................................................92-15
Electrical Wiring Diagram (1/3) (S/N 9351~) ...................................................................................................92-16
Electrical Wiring Diagram (2/3) (S/N 9351~) ...................................................................................................92-17
Electrical Wiring Diagram (3/3) (S/N 9351~) ...................................................................................................92-18
Electrical Wiring Diagram ................................................................................................................................92-19
Way of looking at connectors ....................................................................................................................92-19
Electrical wiring diagram abbreviation chart ....................................................................................................92-21
Electrical Wiring Diagram (CAB) .....................................................................................................................92-23
Electrical Connection Diagram (1/2) (S/N 9001~9250) ...................................................................................92-26
Electrical Connection Diagram (2/2) (S/N 9001~9250) ...................................................................................92-27
Electrical Connection Diagram (1/2) (S/N 9251~9350) ...................................................................................92-28
Electrical Connection Diagram (2/2) (S/N 9251~9350) ...................................................................................92-29
Electrical Connection Diagram (1/2) (S/N 9351~) ...........................................................................................92-30
Electrical Connection Diagram (2/2) (S/N 9351~) ...........................................................................................92-31
Electrical Wiring Diagram (Cabin Air Conditioner) ..........................................................................................92-32
Electrical Circuit Diagram (Cabin Air Conditioner) ..........................................................................................92-33
Equipment Operation Table (Cabin Air Conditioner) .......................................................................................92-34
Electrical Equipment Layout ............................................................................................................................92-35
Electrical Equipment Layout (K-Lever) ............................................................................................................92-46
Outline of MODM (Machine Operation Diagnostic Module) Operation ...........................................................92-47
MODM: Input/Output Monitor - Input/Output Signal Correspondence Table ...................................................92-56

ZW370 FS 00-1
00 General Information
00 General Information
How to Use Manual................................................. 00-2
Outline..................................................................... 00-4

ZW370 FS 00-2
00 General Information
How to Use Manual
How to Use Manual
Safety precautions
The most important point in providing repair service is
safety. To ensure safety, observe the general cautions
described below.
- This manual is intended for properly trained and
equipped service technicians.
- Any work on the machine must be performed by the
trained personnel only.
- Carefully read this manual to thoroughly understand
the operation method before you operate or repair
the machine.
- Be sure to wear appropriate clothes and protectors,
such as safety boots, hard hat and goggles.
- Place the machine on level and solid ground, and
place chocks against the wheels to prevent move-
ment.
- Remove the cable from the battery before starting
the service work, and attach a "DO NOT OPERATE!"
tag to the steering wheel.
- Be sure to release the internal pressure before you
remove a pipe, such as the hydraulic oil, air, or
engine coolant pipe.
- Be sure to apply the articulation stopper before start-
ing work.
- While supporting the bottom of the chassis using a
jack, be sure to support the chassis using the blocks.
- When the boom or bucket is raised or when a unit is
lifted by a crane, be sure to place a stand or ade-
quate cribbing under the unit to prevent unexpected
dropping.
- Do not start to work in an enclosed area if adequate
ventilation is not provided.
- To remove a heavy unit (20 kg (40 lbs) or more), be
sure to use a crane or other lifting device.
- Just after stopping operation, be careful not to
directly touch a hot component. You may get burned.
- Contact tire manufacturer's local dealer for tire ser-
vicing and changing.
- Always store the tools in good condition, and use
them properly.
- Keep the work area clean. Clean up spills immedi-
ately.
- Avoid the use of flammable solvents and cleaners.
- When working outdoors keep work areas, ladders,
steps, decks and work platforms clear of snow, ice,
and mud.
- Use safe work platforms to reach higher areas of the
machine.
- Any technician that operates a refrigerant recovery
and recycling machine must first be certified through
an EPA approved testing program.
More information is available at http://www.epa.gov/
ozone/title6/608/technicians/608certs.html.
IMPORTANT
If a battery terminal is removed from a machine in
less than 30 seconds after the key is put into the
“OFF” position, it can corrupt the ECM program,
which can disable the engine. Always wait 1 full
minute to be sure to be past this “write to memory
function” prior to removing battery terminals.

ZW370 FS 00-3
00 General Information
How to Use Manual
Symbols
For safe and effective service work, the following sym-
bols are used for notes and useful information in this
manual.
Abbreviation
To save space, abbreviations are used in sentences. To understand the contents of this manual, refer to the follow-
ing abbreviation list. Additional abbreviations are listed on page 92-21.
Symbol Item Description
Reference Shows the condition or procedure that will be useful
or efficient in doing service work.
Weight
Shows the weight of a part or unit. The weight
should be considered in selecting wire rope or cable
for slinging work or determining the working pos-
ture.
Tightening
torque Shows the tightening torque of a section that should be carefully tightened during assembly work.
Coating Shows the type of coating or adhesive and the coat-
ing section.
Oil or
water
supply
Shows the oil or water supply port and the refill
amount.
Drainage Shows the oil or water drain port and the drain
amount.
IMPORTANT
If the specified conditions are not satisfied or the specified procedure is not
observed, there is a strong possibility that the product will be damaged or the per-
formance of the product will be reduced.
The message shows the preventive measures.
E/G ........... Engine
T/C ........... Torque converter
T/M ........... Transmission
SOL ........... Solenoid valve
SW ........... Switch
F ........... Front or Forward
A/M ........... Auto/Manual
B ........... Battery
R ........... Rear or Reverse
RH ............Right hand side
LH ............Left hand side
H ............High
L ............Low
GND............Ground
OPT ............Option
Assy............Assembly
1st ............1st speed
2nd ............2nd speed
3rd ............3rd speed
4th ............4th speed
M/C ............Machine
min-1............RPM
ELS ............Efficient loading system
MODM ........Machine operation diag-
nostic module
MCU ...........Machine control unit

ZW370 FS 00-4
00 General Information
Outline
Outline
Layout of main components
95V2E00002
5 6 7 8 10 22
18
11
16
17
20 14 2 15 13 1 1912
38
94 21 3
4
(S/N 9001
~ 9150)