Komatsu WA250-6, WA250PZ-6 Wheel Loader Service Manual
1,295 pages · Publication SEN03813-05
Fast free USA shippingShips in 1 business daySave 10% on 2 manuals, 15% on 3 or morePay by credit or debit card or with PayPal. No PayPal account needed.
Added to your cart. View cart
What's inside
From the manual's own table of contents: 203 sections, 397 entries. See sample pages (PDF, 850 KB)
Composition of shop manual
Safety notice
How to read the shop manual
Explanation of terms for maintenance standard
Handling of electric equipment and hydraulic component
Handling of connectors newly used for engines
How to read electric wire code
Precautions when carrying out operation
Method of disassembling and connecting push-pull type coupler
Standard tightening torque table
Conversion table
Specification dimension drawing
Specifications
Weight table
Table of fuel, coolant and lubricants
Engine mount and transfer mount
Damper
Cooling system
Cooling system hydraulic piping diagram
Cooling fan motor
Power train
Power train system diagram
Drive shaft
HST hydraulic piping diagram
Show all 203 sections
HST pump
HST motor
Transfer
Clutch solenoid valve
Axle
Differential
Torque proportioning differential
Limited slip differential
Final drive
Steering piping diagram
Steering column
Priority valve
Orbit-roll valve
2-way restrictor valve
Cushion valve
Steering cylinder
Emergency steering piping diagram
Emergency steering valve
Steering relief valve46 topics
- Brake piping diagram
- Charge valve
- Brake valve
- Inching valve
- Accumulator (for brake)
- Slack adjuster
- Brake
- Parking brake control
- Parking brake
- Axle mount and center hinge pin
- Tires
- Work equipment hydraulic piping diagram
- Work equipment control lever linkage
- Hydraulic tank
- 4-gear pump
- Work equipment control valve
- PPC valve
- Lock valve
- Accumulator (for PPC circuit)
- Bypass valve
- Quick coupler solenoid valve
- ECSS valve
- Accumulator (for ECSS)
- Work equipment linkage
- Bucket
- Bucket positioner and boom kick-out
- Work equipment cylinder
- Air conditioner
- Machine monitor system
- Machine monitor
- Electrical system (HST controller system)
- HST controller
- ECSS system
- KOMTRAX system
- Engine starting circuit
- Engine stopping circuit
- Preheating circuit
- Engine output derating function
- Automatic warm-up function
- Parking brake circuit
- Coupler plunger control system
- Multi-function knob
- Max. traction switch
- Sensor
- Standard service value table for engine
- Standard service value table for chassis
Tools for testing, adjusting, and troubleshooting
Sketches of special tools
Measuring engine speed
Measuring exhaust gas color
Adjusting valve clearance
Measuring compression pressure
Measuring blow-by pressure
Measuring engine oil pressure
Measuring intake air (boost) pressure
Handling fuel system equipment
Releasing residual pressure in fuel system
Measuring fuel pressure
Measuring fuel return rate and leakage
Bleeding air from fuel circuit
Testing leakage in fuel system
Handling reduced cylinder mode operation
Handling no-injection cranking operation
Handling controller voltage circuit
Check of muffler and muffler stack for looseness and damage
Check of muffler function
Check of installed condition of cylinder head and manifolds
Check of engine piping for damage and looseness
Testing and adjusting air conditioner compressor belt tension
Replacing alternator belt
Checking operating force of accelerator pedal
Checking directional lever
Testing and adjusting HST oil pressure
Testing clutch control pressure
Testing and adjusting steering wheel
Testing and adjusting steering oil pressure
Bleeding air from steering circuit
Testing hydraulic fan
Measuring brake pedal
Testing and adjusting brake pedal linkage
Measuring brake performance
Testing and adjusting accumulator charge pressure
Testing wheel brake oil pressure
Testing wear of brake disc
Bleeding air from wheel brake circuit
Releasing residual pressure in brake accumulator circuit
Testing parking brake performance
Testing and adjusting parking brake control cable
Measuring and adjusting work equipment control lever
Testing and adjusting work equipment hydraulic pressure
Testing work equipment PPC oil pressure
Bleeding air from hydraulic circuit
Releasing remaining pressure in hydraulic circuit
Testing and adjusting bucket positioner
Testing and adjusting of boom kick-out switch
Checking proximity switch operation pilot lamp
Procedure for testing diodes
Preparation work for troubleshooting for electric system
Starting KOMTRAX terminal operations
Indicator lamps of KOMTRAX terminal50 topics
- Adjusting machine monitor
- Adjusting replaced, reassembled or added sensor, controller, etc. with machine monitor
- Special functions of machine monitor (EMMS)
- Pm clinic inspection chart
- Failure codes table
- Fuse locations
- Points to remember when troubleshooting
- Sequence of events in troubleshooting
- Testing before troubleshooting
- Classification and procedures of troubleshooting
- Information contained in troubleshooting table
- Connection table for connector pin numbers
- T- branch box and T- branch adapter table
- Failure code [2G40GZ] Brake: Oil pressure reduction
- Failure code [6091NX] HST filter: Clogging
- Failure code [989FN1] Travel speed: Overrun alarm
- Failure code [AB00L6] Alternator R system: Hot short
- Failure code [AB00MA] Alternator R system: Ground fault/Disconnection charge/Low charge voltage
- Failure code [B@BAZG] Engine: Oil pressure reduction
- Failure code [B@BCNS] Engine: Overheat
- Failure code [B@BCZK] Engine: Low coolant level
- Failure code [B@C6NS] Front brake: High oil temperature
- Failure code [B@CRNS] HST: High oil temperature
- Failure code [CA111] Abnormality in engine controller
- Failure code [CA115] Engine Ne or Bkup speed sensor error
- Failure code [CA122] Charge pressure sensor high error
- Failure code [CA123] Charge pressure sensor low error
- Failure code [CA131] Throttle sensor high error
- Failure code [CA132] Throttle sensor low error
- Failure code [CA144] Coolant sensor high error
- Failure code [CA145] Coolant sensor low error
- Failure code [CA153] Charge temperature sensor high error
- Failure code [CA154] Charge temperature sensor low error
- Failure code [CA155] Derating of speed by abnormally high charge temperature
- Failure code [CA187] Sensor power supply 2 low error
- Failure code [CA221] Atmospheric pressure sensor high error
- Failure code [CA222] Atmospheric sensor low error
- Failure code [CA227] Sensor power supply 2 high error
- Failure code [CA234] Engine overspeed
- Failure code [CA238] Ne speed sensor power supply error
- Failure code [CA271] IMV (IMA) Short circuit
- Failure code [CA272] IMV (IMA) Disconnection
- Failure code [CA322] Injector #1 open/short error
- Failure code [CA323] Injector #5 open/short error
- Failure code [CA324] Injector #3 open/short error
- Failure code [CA325] Injector #6 open/short error
- Failure code [CA331] Injector #2 open/short error
- Failure code [CA332] Injector #4 open/short error
- Failure code [CA342] Calibration code inconsistency
- Failure code [CA351] Injectors drive circuit error
Failure code [CA352] Sensor power supply 1 low error
Failure code [CA386] Sensor power supply 1 high error
Failure code [CA428] Abnormally high level in water sensor
Failure code [CA429] Abnormally low level in water sensor
Failure code [CA431] Idle validation switch error
Failure code [CA432] Idle validation action error
Failure code [CA435] Engine oil pressure switch error
Failure code [CA441] Battery voltage low error
Failure code [CA442] Battery voltage high error
Failure code [CA449] Common rail pressure high error 2
Failure code [CA451] Common rail pressure sensor high error
Failure code [CA452] Common rail pressure sensor low error
Failure code [CA488] Derating of torque by abnormally high charge temperature
Failure code [CA553] Common rail pressure high error 1
Failure code [CA559] Supply pump pressure very low error
Failure code [CA689] Engine Ne speed sensor error
Failure code [CA731] Engine Bkup speed sensor phase error
Failure code [CA757] All continuous data lost error
Failure code [CA778] Engine Bkup speed sensor error
Failure code [CA1633] KOMNET datalink timeout error
Failure code [CA2185] Throttle sensor supply voltage high error
Failure code [CA2186] Throttle sensor power supply low error
Failure code [CA2249] Supply pump pressure very low error 2
Failure code [CA2311] Abnormality in IMV (IMA) solenoid
Failure code [CA2555] Intake heater relay disconnection error
Failure code [CA2556] Intake heater relay short circuit error
Failure code [D160KY] Backup alarm/lamp relay 1 circuit: Hot short
Failure code [D192KY] ECSS solenoid relay: Hot short
Failure code [D1B0KA] HST safety relay: Disconnection
Failure code [D1B0KB] HST safety relay: Ground fault
Failure code [D1B0KY] HST safety relay: Hot short
Failure code [D5ZHL6] IGN C system: Ground fault/Disconnection
Failure code [DAF3KK] UNSW power supply: Ground fault/Disconnection
Failure code [DAFRKR] Machine monitor CAN-NET Signal: Disconnection
Failure code [DAJ0KK] HST controller power supply: Low voltage
Failure code [DAJ0KT] HST controller memory (EEPROM): Abnormality
Failure code [DAJ1L4] HST controller main power line: Disconnection/Ground fault
Failure code [DAJ1L6] HST controller main power line: Hot short
Failure code [DAJ2KK] Controller solenoid power supply: Low voltage
Failure code [DAJ2L3] HST controller load power supply holding line: Hot short in wiring harness
Failure code [DAJ2L4] HST controller load power supply holding line: Disconnection/Ground fault
Failure code [DAJ5KX] Sensor 5V power supply: Out of output range
Failure code [DAJ9KQ] HST controller model selection: Disagreement of model selection signals
Failure code [DAJRKR] HST controller CAN-NET signal: Disconnection
Failure code [DAJRMA] HST controller: Disagreement in option selection
Failure code [DB2RKR] Engine controller CAN-NET: Disconnection in signal line
Failure code [DD1NL4] Fan automatic reverse switch signal: Abnormality
Failure code [DD1NLD] Fan reverse switch signal: Abnormality
Failure code [DDB6KA] Parking brake switch A: Disconnection/Hot short
Failure code [DDB6KB] Parking brake switch B: Ground fault1 topic
- (intermediate switch): Trouble
Failure code [DDB6L0] Parking brake switch A: Ground fault
Failure code [DDB6L4] Parking brake switch B: Disconnection/Hot short
Failure code [DDD7KX] Travel speed control dial signal: Disconnection/Ground fault55 topics
- Failure code [DDD7KY] Travel speed control dial signal: Hot short
- Failure code [DDE5MA] Emergency steering operation switch: Disconnection
- Failure code [DDK3KA] Directional selector switch: Disconnection/Hot short
- Failure code [DDK3KB] Directional selector switch: Ground fault
- Failure code [DDK6KA] FNR lever: Disconnection/Ground fault
- Failure code [DDK6KY] FNR lever: Hot short
- Failure code [DDS5L6] Steering: Low oil pressure (Operation of emergency steering)
- Failure code [DF10KA] Travel speed range selector switch: Disconnection/Ground fault
- Failure code [DF10KB] Travel speed range selector switch: Hot short
- Failure code [DGH1KX] HST oil temperature sensor: Ground fault
- Failure code [DGR2KB] Brake oil temperature sensor: Ground fault
- Failure code [DGR2KZ] Brake oil temperature sensor: Disconnection/Hot short
- Failure code [DHH1KX] HST oil pressure sensor: Disconnection/Ground fault
- Failure code [DHH1KY] HST oil pressure sensor: Hot short
- Failure code [DHTCL6] HST filter clogging sensor: Functional defect
- Failure code [DJF1KA] Fuel level sensor: Disconnection/Hot short
- Failure code [DLT3KX] Travel speed sensor B: Abnormality
- Failure code [DLT4KX] Travel speed sensor A: Abnormality
- Failure code [DLT4LC] Travel speed sensor A & B: Abnormality
- Failure code [DV00KY] Alarm buzzer: Hot short
- Failure code [DW26KA] Motor 2 solenoid: Disconnection/Ground fault
- Failure code [DW26KY] Motor 2 solenoid: Hot short
- Failure code [DW7BKY] Fan reverse solenoid circuit: Hot short
- Failure code [DW7BKZ] Fan reverse solenoid circuit: Disconnection/Ground fault
- Failure code [DX16KA] Fan EPC solenoid: Disconnection
- Failure code [DX16KB] Fan EPC solenoid: Ground fault
- Failure code [DX16KY] Fan EPC solenoid: Hot short
- Failure code [DX19KA] Motor 1 solenoid: Disconnection
- Failure code [DX19KB] Motor 1 solenoid: Ground fault
- Failure code [DX19KY] Motor 1 solenoid: Hot short
- Failure code [DX20KA] Clutch EPC solenoid: Disconnection
- Failure code [DX20KB] Clutch EPC solenoid: Ground fault
- Failure code [DX20KY] Clutch EPC solenoid: Hot short
- Failure code [DXH7KB] Reverse solenoid: Ground fault
- Failure code [DXH7KZ] Reverse solenoid: Disconnection/Hot short
- Failure code [DXH8KB] Forward solenoid: Ground fault
- Failure code [DXH8KZ] Forward solenoid: Disconnection/Hot short
- Failure code [J141N1] Steering pump: Overrun alarm
- Failure code [M100N1] HST pump: Overrun alarm
- Failure code [M400N1] Motor 1: Overrun alarm
- Engine does not start
- Preheater does not operate normally
- Defective boom kick-out function and cancellation
- Defective bucket positioner function and cancellation
- Defective lift arm FLOATING holding function and cancellation
- Travel direction selection system does not function
- Wiper does not operate
- Windshield washer does not operate
- Headlamp, clearance lamp and tail lamp do not light up or go off
- Working lamp does not light up or go off
- Turn signal lamp and hazard lamp do not light up or go off
- Brake lamp does not light or it keeps lighting up
- Backup lamp does not light or it keeps lighting up
- Backup alarm does not sound or it keeps sounding
- Horn does not sound or it keeps sounding
Alarm buzzer does not sound or it keeps sounding
Air conditioner does not operate or stop
The KOMTRAX system does not work properly
Method of using troubleshooting chart
Failure code and cause table
The machine does not start
The travel speed is slow
The traction force is weak
Engine stalls when traveling or engine speed drops excessively
The gear is not shifted
The steering wheel does not turn
The steering wheel is heavy
Steering wheel shakes or jerks
Machine deviates naturally to one side when traveling
The brake does not work or does not work well
The brake is not released or is dragged
The lift arm does not rise or lower
The lift arm moves slowly or the lift arm rising force is insufficient
When rising, the lift arm comes to move slowly at specific height
The lift arm cylinder cannot hold down the bucket (The bucket rises in the air)
Hydraulic drifts of the lift arm occur often
The lift arm wobbles during operation
When the control lever is switched from “HOLD” to “RAISE,” the lift arm falls temporarily
The bucket does not tilt back
The bucket moves slowly or the tilting-back force is insufficient
The bucket comes to operate slowly in the midst of tilting-back
The bucket cylinder cannot hold down the bucket
Hydraulic drifts of the bucket occur often
The bucket wobbles during travel with load (The work equipment valve is set to “HOLD”)
When the control lever is switched from “HOLD” to “TILT,” the bucket falls temporarily
The control levers of the lift arm and bucket do not move smoothly and heavy
The ECSS does not operate and machine pitches and bounces
Fan revolution is abnormal (Fan sound/vibration is abnormally large or engine overheats)
Method of using troubleshooting charts
Starting performance is poor
Engine does not start
Engine does not pick up smoothly
Engine stops during operations
Engine does not rotate smoothly
Engine lacks output (or lacks power)
Exhaust smoke is black (incomplete combustion)
Oil consumption is excessive (or exhaust smoke is blue)
Oil becomes contaminated quickly
Fuel consumption is excessive
Oil is in coolant (or coolant spurts back or coolant level goes down)
Oil pressure drops
Oil level rises (Entry of coolant or fuel)
Coolant temperature becomes too high (overheating)
Abnormal noise is made
Vibration is excessive42 topics
- How to read this manual
- Coating materials list
- Special tool list
- Sketches of special tools
- Removal and installation of fuel supply pump assembly
- Removal and installation of fuel injector assembly
- Removal and installation of cylinder head assembly
- Removal and installation of engine hood assembly
- Removal and installation of radiator
- Removal and installation of air aftercooler
- Removal and installation of hydraulic oil cooler assembly
- Removal and installation of engine assembly
- Removal and installation of engine front oil seal assembly
- Removal and installation of engine rear oil seal assembly
- Removal and installation of cooling fan and fan motor assembly
- Removal and installation of fuel tank assembly
- Removal and installation of transfer assembly
- Disassembly and assembly of transfer assembly
- Removal and installation of parking brake assembly
- Disassembly and assembly of parking brake assembly
- Removal and installation of front axle assembly
- Removal and installation of rear axle assembly
- Disassembly and assembly of axle housing assembly
- Disassembly and assembly of differential assembly
- Removal and installation of center hinge pin
- Removal and installation of counterweight
- Removal and installation of HST pump and 4-gear pump assembly
- Disassembly and assembly of HST pump assembly
- Removal and installation of HST motor 1 assembly
- Removal and installation of HST motor 2 assembly
- Disassembly and assembly of HST motor assembly
- Removal and installation of work equipment control valve assembly
- Removal and installation of hydraulic tank
- Disassembly and assembly of hydraulic cylinder assembly
- Removal and installation of work equipment assembly
- Removal and installation of operator's cab and floor frame assembly
- Removal and installation of operator's cab glass (Stuck glass)
- Removal and installation of air conditioner unit
- Removal and installation of monitor panel
- Removal and installation of engine controller assembly
- Removal and installation of HST controller assembly
- Removal and installation of KOMTRAX terminal assembly
Hydraulic circuit diagram
Electrical circuit diagram
Connector list and stereogram
Inside this manual
Real pages from this service manual (1,295 pages). Open the sample pages (PDF, 849 KB)
- Troubleshooting, page 554: 200 General information on troubleshooting
- Diagram, page 934: 400 Troubleshooting of electrical system (E-mode)
- Specifications, page 1,154: 320 Power train, Part 2
- Foldout diagram, page 1,284: Electrical circuit diagram (1/9)
Other manuals for this machine
Save 10% on 2 manuals, 15% on 3 or more. Other manuals are listed below. Editions cover different serial number ranges: check the serial coverage and tick only the ones that match your machine.
This manual: Service Manual SEN03813-05$129.97
Added to your cart. View cart
This is a service manual
Here's how it compares to the other manual types.
This manual
Service manual
Factory repair procedures and technical information such as specifications, troubleshooting, and wiring and hydraulic diagrams, for the models and systems the manual covers. See What's inside for its topics.
Operator's manual
Safe operation, controls, maintenance schedules, lubrication points, inspections, and basic checks. Repair procedures are in the service manual.
Parts manual
Illustrated diagrams with factory part numbers for identifying components and ordering parts. Repair procedures are in the service manual.
Engine service manuals are sometimes sold separately, since certain machine models were offered with more than one engine option.
What it's used for
Factory manual for in-house farm and construction shop use. Straightforward, complete, and easy to follow. It contains the OEM information dealership service departments and parts counters use to diagnose problems, identify components, and perform maintenance or repairs correctly.
Service shops and owner/operators who repair their own equipment
Identifying correct parts and seeing how assemblies come apart and go back together
Keeping equipment running with less downtime
Factory manual, 1,295 pages
Quantity one is the manual described above.
Fast free USA shipping
Ships in 1 business day.
60-day returns
Free if the mistake is ours. A manual ordered in error must come back unopened in its shrink-wrap; you pay return shipping and a 20% restocking fee applies. Return policy
Binder not included
Manuals over about 300 pages may need a standard 3-ring binder, which you can buy locally to keep the pages organized for shop use.
Other editions and similar models
Questions about model, serial number, engine coverage or contents? Contact us before purchasing and we'll help confirm it's the right manual. Please verify the manual type, machine model, serial number range and engine coverage before purchasing: manuals ordered in error carry a 20% restocking fee (return policy).