Komatsu WA270-7 Wheel Loader Service Repair Manual SN A27001 & Up

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This service manual contains detailed maintenance, service, repair and troubleshooting procedures for the WA270-7 Wheel Loader (SN A27001 & Up). The service manual is a must for all WA270-7 Wheel Loader (SN A27001 & Up) owners, operators and mechanics. Print off the pages including detailed diagrams and accurate illustrations you need at any time and save time and money on repair.

Topics in the Komatsu WA270-7 Wheel Loader Service Manual (SN A27001 & Up):

Specifications
Specification drawing
Specifications
Weight table
Table of fuel, coolant, and lubricants

Structure and function
Engine and cooling system
Engine related parts
KVGT
EGR system piping drawing
EGR system circuit diagram
EGR valve
EGR cooler
KCCV layout drawing
KCCV ventilator
KDPF
Cooling system
Cooling fan motor
Power train
Power train system
Layout of power train parts
Damper
HST pump
HST motor1
HST motor2
Transfer
Clutch solenoid valve
Drive shaft
Axle
Differential
Torque proportional differential
Limited slip differential
Final drive
Steering system
Layout of steering devices
Steering column
Priority valve
Cushion valve
00-2 WA270-7
00 Index and foreword
Index
Emergency steering valve
Orbitrol valve
2way restrictor valve
Brake system
Layout of brake parts
Brake accumulator charge valve
Brake valve
Brake accumulator
Slack adjuster
Brake
Parking brake control
Parking brake
Parking brake solenoid valve
Undercarriage and frame
Axle mount
Center hinge pin
Tire
Hydraulic system
Hydraulic component layout
Work equipment control
Hydraulic tank
Double type gear pump
Steering and work equipment pump
Control valve
CLSS
Hydraulic circuit diagram and names of valves
Self-pressure reducing valve
Work equipment PPC valve
Work equipment lock solenoid valve
PPC circuit accumulator
ECSS accumulator
Work equipment
Work equipment linkage
Bucket
Cab and its attachments
ROPS cab
Cab mount
Electrical system
Engine control system
Preheating system
Engine output limit function
Automatic warm-up function
Parking brake control system
System operating lamp function
Battery disconnect switch function
HSTcontroller system
Machine monitor system
Rearview monitor system
KOMTRAX system
System component parts
Sensor

Standard value tables
Standard service value table
Standard value table for engine
Standard value table for machine
Standard value table for electrical system

Testing and adjusting
Related information on testing and adjusting
Tools for testing and adjusting
Sketch of tools for testing and adjusting
Engine and cooling system
Testing engine speed
Testing boost pressure
Testing exhaust gas temperature
Testing exhaust gas color
Testing and adjusting valve clearance
Testing compression pressure
Testing blowby pressure
Testing engine oil pressure
Testing EGR valve and KVGT driving oil pressure
Testing fuel pressure
Testing fuel discharge, return and leakage
Bleeding air from fuel system
Testing fuel circuit for leakage
Handling cylinder cutout mode operation
Handling no-injection cranking operation
Testing of KDPF and muffler stack for looseness and damage
Testing of installed condition of cylinder heads and manifolds
Testing engine piping for damage and looseness
Testing and adjusting air conditioner compressor belt tension
Replacing alternator belt
Power train
Testing oil leakage from axle final drive
Testing drive shaft for looseness, backlash, and damage
Testing accelerator pedal
Testing and adjusting HSToil pressure
Testing transfer clutch control pressure
Steering system
Testing directional lever
Testing steering wheel
Testing work equipment control lever
Testing and adjusting steering circuit oil pressure
Bleeding air from steering cylinder circuit
Brake system
Testing brake pedal
Testing braking performance
Testing and adjusting of accumulator charge pressure
Testing wheel brake oil pressure
Testing lowering of wheel brake pressure
Testing wear of wheel brake disc
Bleeding air from wheel brake circuit
Releasing remaining pressure in brake accumulator circuit
Testing parking brake performance
Testing wear of parking brake disc
Testing parking brake release pressure
Method of releasing parking brake manually
Hydraulic system
Testing cooling fan speed
Testing cooling fan pump circuit oil pressure
Bleeding air from hydraulic fan circuit
Testing and adjusting work equipment PPC oil pressure
Testing and adjusting work equipment oil pressure
Bleeding air from work equipment circuit
Releasing remaining pressure from work equipment circuit
Testing ECSS accumulator nitrogen gas pressure and procedure for charging accumulator with
nitrogen gas
00-4 WA270-7
00 Index and foreword
Index
Work equipment
Testing and adjusting bucket positioner and bucket proximity switch
Testing and adjusting boom position detection lever
Electrical system
Adjusting replaced, reassembled or added sensor, controller, etc
monitor
Special functions of machine monitor
Adjusting rearview camera angle
Handling voltage circuit of engine controller
Handling battery disconnect switch
Testing diodes
Pm clinic
Pm Clinic service
Check sheet

Troubleshooting
Related information on troubleshooting
Troubleshooting points
Sequence of events in troubleshooting
Checks before troubleshooting
Inspection procedure before troubleshooting
Preparation for troubleshooting of electrical system
Classification and procedures for troubleshooting
Symptom and troubleshooting numbers
Information described in troubleshooting table
Procedure for troubleshooting wiring harness of pressure sensor system for open circuit
Connector list and layout
Connector contact identification
T-branch box and T-branch adapter table
Fuse location table
Precautions for KDPF (KCSF and KDOC) Cleaning and Replacement
Precautions when performing troubleshooting of machine monitor
Processing procedure of harness checker for troubleshooting of machine monitor LCD unit
Preparation of dummy temperature sensor (for KDOC and KDPF temperature sensors)
Preparation of short circuit electrical connector (for failure codes [CA1883] and [CA3135])
Failure codes table
Troubleshooting by failure code (Display of code)
Failure code [2F00MA] Failure of Parking Brake Circuit
Failure code [2F00MB] Malfunction of Parking Brake
Failure code [2G42ZG] Accumulator Oil Pressure Low (Front)
Failure code [2G43ZG] Accumulator Oil Pressure Low (Rear)
Failure code [6091NX] HST Oil Filter Clogging
Failure code [7RHYKA] Disconnection of Fan Variable Control Sol
Failure code [7RHYKB] Ground Fault of Fan Variable Control Sol
Failure code [7RHYKY] Hot Short of Fan Variable Control Sol
Failure code [879AKA] A/C Inner Sensor Open Circuit
Failure code [879AKB] A/C Inner Sensor Short Circuit
Failure code [879BKA] A/C Outer Sensor Open Circuit
Failure code [879BKB] A/C Outer Sensor Short Circuit
Failure code [879CKA] Ventilating Sensor Open Circuit
Failure code [879CKB] Ventilating Sensor Short Circuit
Failure code [879DKZ] Sunlight Sensor Open or Short Circuit
Failure code [879EMC] Ventilation Damper Abnormality
Failure code [879FMC] Air Mix Damper Abnormality
Failure code [989L00] Engine Controller Lock Caution 1
Failure code [989M00] Engine Controller Lock Caution 2
Failure code [989N00] Engine Controller Lock Caution 3
Failure code [A1U0N3] HC Desorb Request 1
Failure code [A1U0N4] HC Desorb Request 2
Failure code [B@BAZG] Eng Oil Press Low
Failure code [B@BCNS] Eng Water Overheat
Failure code [B@BCZK] Eng Water Level Low
Failure code [B@CRNS] HST Oil Temp
Failure code [CA115] Eng Ne and Bkup Speed Sens Error
Failure code [CA122] Chg Air Press Sensor High Error
Failure code [CA123] Chg Air Press Sensor Low Error
Failure code [CA131] Throttle Sensor High Error
Failure code [CA132] Throttle Sensor Low Error
Failure code [CA144] Coolant Temp Sens High Error
Failure code [CA145] Coolant Temp Sens Low Error
Failure code [CA153] Chg Air Temp Sensor High Error
Failure code [CA154] Chg Air Temp Sensor Low Error
Failure code [CA187] Sensor 2 Supply Volt Low Error
Failure code [CA221] Ambient Press Sensor High Error
Failure code [CA222] Ambient Press Sensor Low Error
Failure code [CA227] Sensor 2 Supply Volt High Error
Failure code [CA234] Eng Overspeed
Failure code [CA238] Ne Speed Sensor Supply Volt Error
Failure code [CA239] Ne Speed Sens Supply Volt High Error
Failure code [CA271] IMV/PCV1 Short Error
Failure code [CA272] IMV/PCV1 Open Error
Failure code [CA295] Ambient Press Sens In Range Error
Failure code [CA322] Inj #1(L#1) Open/Short Error
Failure code [CA323] Inj #5(L#5) Open/Short Error
Failure code [CA324] Inj #3(L#3) Open/Short Error
Failure code [CA325] Inj #6(L#6) Open/Short Error
Failure code [CA331] Inj #2(L#2) Open/Short Error
Failure code [CA332] Inj #4(L#4) Open/Short Error
Failure code [CA343] ECM Critical Internal Failure
Failure code [CA351] Injectors Drive Circuit Error
Failure code [CA352] Sensor 1 Supply Volt Low Error
Failure code [CA356] Mass Air Flow Sensor High Error
Failure code [CA357] Mass Air Flow Sensor Low Error
Failure code [CA386] Sensor 1 Supply Volt High Error
Failure code [CA428] Water in Fuel Sensor High Error
Failure code [CA429] Water in Fuel Sensor Low Error
Failure code [CA431] Idle Validation Sw Error
Failure code [CA432] Idle Validation Process Error
Failure code [CA435] Eng Oil Press Sw Error
Failure code [CA441] Battery Voltage Low Error
Failure code [CA442] Battery Voltage High Error
Failure code [CA449] Rail Press Very High Error
Failure code [CA451] Rail Press Sensor High Error
Failure code [CA452] Rail Press Sensor Low Error
Failure code [CA488] Chg Air Temp High Torque Derate
Failure code [CA515] Rail Press Sens Sup Volt High Error
Failure code [CA516] Rail Press Sens Sup Volt Low Error
Failure code [CA553] Rail Press High Error
Failure code [CA555] Crankcase Press High Error 1
Failure code [CA556] Crankcase Press High Error 2
Failure code [CA559] Rail Press Low Error
Failure code [CA595] Turbo Speed High Error 2
Failure code [CA687] Turbo Speed Low Error
Failure code [CA689] Eng Ne Speed Sensor Error
Failure code [CA691] Intake Air Temp Sens High Error
Failure code [CA692] Intake Air Temp Sens Low Error
Failure code [CA697] ECM Internal Temp Sensor High Error
Failure code [CA698] ECM Int Temp Sensor Low Error
Failure code [CA731] Eng Bkup Speed Sens Phase Error
Failure code [CA778] Eng Bkup Speed Sensor Error
Failure code [CA1117] Persistent Data Lost Error
Failure code [CA1664] KDOC Malfunction
Failure code [CA1691] Regeneration Ineffective
Failure code [CA1695] Sensor 5 Supply Volt High Error
Failure code [CA1696] Sensor 5 Supply Volt Low Error
Failure code [CA1843] Crankcase Press Sens High Error
Failure code [CA1844] Crankcase Press Sens Low Error
Failure code [CA1879] KDPF Delta P Sensor High Error
Failure code [CA1881] KDPF Delta P Sensor Low Error
Failure code [CA1883] KDPF Delta P Sens In Range Error
Failure code [CA1921] KDPF Soot Load High Error 1
Failure code [CA1922] KDPF Soot Load High Error 2
Failure code [CA1942] Crankcase Press Sens In Range Error
Failure code [CA1993] KDPF Delta Pressure Low Error
Failure code [CA2185] Throt Sensor Sup Volt High Error
Failure code [CA2186] Throt Sensor Sup Volt Low Error
Failure code [CA2249] Rail Press Very Low Error
Failure code [CA2271] EGR Valve Pos Sens High Error
Failure code [CA2272] EGR Valve Pos Sens Low Error
Failure code [CA2288] Turbo Speed High Error 1
Failure code [CA2311] IMV Solenoid Error
Failure code [CA2349] EGR Valve Solenoid Open Error
Failure code [CA2353] EGR Valve Solenoid Short Error
Failure code [CA2357] EGR Valve Servo Error
Failure code [CA2373] Exhaust Manifold Press Sens High error
Failure code [CA2374] Exhaust Manifold Press Sens Low error
Failure code [CA2375] EGR Orifice Temp Sens High Error
Failure code [CA2376] EGR Orifice Temp Sens Low Error
Failure code [CA2381] KVGT Pos Sens High Error
Failure code [CA2382] KVGT Pos Sens Low Error
Failure code [CA2383] KVGT Solenoid Open Error
Failure code [CA2386] KVGT Solenoid Short Error
Failure code [CA2387] KVGT Servo Error
Failure code [CA2554] Exh Manifold Press Sens In Range Error
Failure code [CA2555] Grid Htr Relay Volt Low Error
Failure code [CA2556] Grid Htr Relay Volt High Error
Failure code [CA2637] KDOC Face Plugging
Failure code [CA2639] Manual Stationary Regeneration Request
Failure code [CA2961] EGR Orifice Temp High Error 1
Failure code [CA2973] Chg Air Press Sensor In Range Error
Failure code [CA3133] KDPF Outlet Press Sens High Error
Failure code [CA3134] KDPF Outlet Press Sens Low Error
Failure code [CA3135] KDPF Outlet Press Sens In Range Error
Failure code [CA3251] KDOC Inlet Temp High Error
Failure code [CA3253] KDOC Temp Error – Non Regeneration
Failure code [CA3254] KDOC Outlet Temp High Error 1
Failure code [CA3255] KDPF Temp Error – Non Regeneration
Failure code [CA3256] KDPF Outlet Temp High Error 1
Failure code [CA3311] KDOC Outlet Temp High Error 2
Failure code [CA3312] KDPF Outlet Temp High Error 2
Failure code [CA3313] KDOC Inlet Temp Sensor Low Error
Failure code [CA3314] KDOC Inlet Temp Sens High Error
Failure code [CA3315] KDOC Inlet Temp Sens In Range Error
Failure code [CA3316] KDOC Outlet Temp Sens Low Error
Failure code [CA3317] KDOC Outlet Temp Sens High Error
Failure code [CA3318] KDOC Outlet Temp Sens In Range Error
Failure code [CA3319] KDPF Outlet Temp Sens High Error
Failure code [CA3321] KDPF Outlet Temp Sens Low Error
Failure code [CA3322] KDPF Outlet Temp Sens In Range Error
Failure code [CA3419] Mass Air Flow Sensor Sup Volt High Error
Failure code [CA3421] Mass Air Flow Sensor Sup Volt Low Error
Failure code [CA3741] Rail Press Valve Trip Error
Failure code [D110L4] Disconnection of Battery Relay Signal
Failure code [D160KA] Disconnection of Backup Lamp Relay Output
Failure code [D160KY] Hot Short of Backup Lamp Relay Output
Failure code [D191KA] Disconnection of Neutral Output Relay
Failure code [D191KB] Ground Fault of Neutral Output Relay
Failure code [D191KY] Hot Short of Neutral Output Relay
Failure code [D192KA] Disconnection of ECSS Solenoid
Failure code [D192KB] Ground Fault of ECSS Solenoid
Failure code [D192KY] Hot Short of ECSS Solenoid
Failure code [D19JKZ] Personal Code Relay Abnormality
Failure code [D1B0KA] Disconnection of HST Safety Relay
Failure code [D1B0KB] Ground Fault of HST Safety Relay
Failure code [D1B0KY] Hot Short of HST Safety Relay
Failure code [D1B0MC] Malfunction of HST Safety Relay
Failure code [D1E6KA] Disconnection of Parking Brake Relay
Failure code [D1E6KB] Ground Fault of Parking Brake Relay
Failure code [D1E6KY] Hot Short of Parking Brake Relay
Failure code [D5ZHKA] Failure of Key SW C Signal
Failure code [D5ZHKB] Key SW C Signal Short Circuit
Failure code [D5ZHL6] Disconnection of Key SW C
Failure code [D811MC] KOMTRAX Error
Failure code [D862KA] GPS Antenna Open Circuit
Failure code [D8ALKA] Operating Lamp Open Circuit (KOMTRAX)
Failure code [D8ALKB] Operating Lamp Short Circuit (KOMTRAX)
Failure code [D8AQK4] CAN2 Discon (KOMTRAX) 2
Failure code [D8AQKR] CAN2 Discon (KOMTRAX)
Failure code [DAF0KT] Abnormality of Non-volatile Memory (MON)
Failure code [DAF0MB] Monitor ROM Abnormality
Failure code [DAF0MC] Monitor Error
Failure code [DAF3KK] Controller Power Source Low (MON)
Failure code [DAF8KB] Camera Power Supply Short Circuit
Failure code [DAFDKB] Monitor 12V Power Output Short Circuit
Failure code [DAFGMC] GPS Module Error
Failure code [DAFLKA] Operating Lamp Open Circuit (MON)
Failure code [DAFLKB] Operating Lamp Short Circuit (MON)
Failure code [DAFQKR] CAN2 Discon (Monitor)
Failure code [DAJ0KK] Controller Power Source Low (HST)
Failure code [DAJ0KT] Abnormality of Non-volatile Memory (HST)
Failure code [DAJ0MC] HST Con Error
Failure code [DAJ1KA] Disconnection of Key SW ACC (HST)
Failure code [DAJ2KK] Solenoid Power Source Low (HST)
Failure code [DAJ4KB] Ground Fault of Sol
Failure code [DAJ4KZ] Failure of Sol
Failure code [DAJ5KX] Failure of 5V Power Source 0
Failure code [DAJ6KX] Failure of 5V Power Source 1
Failure code [DAJ9KQ] Inconsistency of Model Selection (HST)
Failure code [DAJLKA] Operating Lamp Open Circuit (HST)
Failure code [DAJLKB] Operating Lamp Short Circuit (HST)
Failure code [DAJQKR] CAN2 Discon ( HST Con)
Failure code [DAJRKR] CAN1 Discon ( HST Con)
Failure code [DAJRMA] Inconsistency of Option Selection (HST)
Failure code [DAZ9KQ] A/C Model Selection Abnormality
Failure code [DAZQKR] CAN2 Discon (Aircon ECU)
Failure code [DB2QKR] CAN2 Discon (Engine Con)
Failure code [DB2RKR] CAN1 Discon (Engine Con)
Failure code [DD1ALD] Ground Fault of Remote Positioner Set SW
Failure code [DDAAL6] Discon of Engine Shutdown Secondary Switch
Failure code [DDB2L4] Stop Lamp Switch Signal Malfunction
Failure code [DDB6L4] Parking Brake Signal Malfunction
Failure code [DDD7KA] Failure of Variable Speed Control
Failure code [DDD7KY] Hot Short of Variable Speed Control
Failure code [DDK3KA] FNR SW Input Signal Disconnection
Failure code [DDK3KB] FNR SW Input Signal Short Circuit
Failure code [DDK6KA] FNR Lever Input Signal Disconnection
Failure code [DDK6KB] FNR Lever Input Signal Short Circuit
Failure code [DDNRLD] Ground Fault of Work Equip
Failure code [DF10KA] Disconnection of Speed Range Input
Failure code [DF10KB] Ground Fault of Speed Range Input
Failure code [DGR2KB] Ground Fault of Brake Oil Temp
Failure code [DGR2KZ] Failure of Brake Oil Temp
Failure code [DHG1KX] Out of Range of HST Oil Temp
Failure code [DHHBKA] Failure of HST Press
Failure code [DHHBKY] Hot Short of HST Press
Failure code [DHHCKA] Failure of HST Press
Failure code [DHHCKY] Hot Short of HST Press
Failure code [DHPCKA] Failure of Boom Press
Failure code [DHPCKY] Hot Short of Boom Press
Failure code [DHPEKA] Failure of Steering & Loader Pump Press
Failure code [DHPEKY] Hot Short of Steering & Loader Pump Press
Failure code [DHS8KA] Failure of Boom Raise PPC Sens
Failure code [DHS8KY] Hot Short of Boom Raise PPC Sens
Failure code [DHS9KA] Failure of Boom Lower PPC Sens
Failure code [DHS9KY] Hot Short of Boom Lower PPC Sens
Failure code [DHSDKA] Failure of Bucket Dump PPC Sens
Failure code [DHSDKY] Hot Short of Bucket Dump PPC Sens
Failure code [DHSNKA] Failure of Bucket Tilt PPC Sens
Failure code [DHSNKY] Hot Short of Bucket Tilt PPC Sens
Failure code [DHT8ZG] Steering Oil Pressure Low
Failure code [DHTCL6] Failure of HST Oil Filter Sensor Circuit
Failure code [DJF1KA] Disconnection of Fuel Level Sensor
Failure code [DK55KA] Failure of FNR Lever Potentio
Failure code [DK55KY] Hot Short of FNR Lever Potentio Circuit
Failure code [DK55L5] Failure of FNR Lever Potentio
Failure code [DK5DKA] Failure of 3rd Lever Potentio (Main)
Failure code [DK5DKY] Hot Short of 3rd Lever Potentio (Main)
Failure code [DK5DL8] 3rd Lever Potentio (Main & Sub) Disagree
Failure code [DK5EKA] Failure of 3rd Lever Potentio (Sub)
Failure code [DK5EKY] Hot Short of 3rd Lever Potentio (Sub)
Failure code [DK70KA] Failure of inching sensor Circuit
Failure code [DK70KY] Hot Short of inching sensor Circuit
Failure code [DKA0KA] Failure of Boom Angle Sensor
Failure code [DKA0KY] Hot Short of Boom Angle Sensor Circuit
Failure code [DKA0L0] Boom Angle Sensor Dislocation
Failure code [DLM3KA] Disconnection of Radiator Fan Speed Sensor
Failure code [DLM3LC] Failure of Radiator Fan Speed Sensor
Failure code [DLT3KX] Vehicle Speed Sensor Circuit Failure (B)
Failure code [DLT4KX] Vehicle Speed Sensor Circuit Failure (A)
Failure code [DLT4L0] Vehicle Speed Sensor Failure (A & B)
Failure code [DLT4LC] Vehicle Speed Sensor Failure (A or B)
Failure code [DPQ1KR] LIN Discon (Switch Panel)
Failure code [DPQ2KR] LIN Discon (LED Unit)
Failure code [DPQ3KR] LIN Discon (Rear View Monitor)
Failure code [DSJ0KR] CAN2 Discon (Meter Unit)
Failure code [DT22KB] Ground Fault of Work Equip
Failure code [DV00KB] Ground Fault of Buzzer Output
Failure code [DW26KA] Disconnection of Motor 2 Solenoid
Failure code [DW26KB] Ground Fault of Motor 2 Solenoid
Failure code [DW26KY] Hot Short of Motor 2 Solenoid
Failure code [DW4BKA] Disconnection of Parking Brake Valve
Failure code [DW4BKB] Ground Fault of Parking Brake Valve
Failure code [DW4BKY] Hot Short of Parking Brake Valve
Failure code [DW4RKA] Disconnection of Bucket EPC Sol
Failure code [DW4RKB] Ground Fault of Bucket EPC Solenoid (Tilt)
Failure code [DW4RKY] Hot Short of Bucket EPC Solenoid (Tilt)
Failure code [DWM1KA] Disconnection of Neutral Lock Solenoid
Failure code [DWM1KB] Ground Fault of Neutral Lock Solenoid
Failure code [DWM1KY] Hot Short of Neutral Lock Solenoid
Failure code [DWN6KA] Disconnection of Detent Solenoid (Boom)
Failure code [DWN6KB] Ground Fault of Detent Solenoid (Boom)
Failure code [DWN6KY] Hot Short of Detent Solenoid (Boom)
Failure code [DWN8KA] Disconnection of Detent Solenoid (Bucket)
Failure code [DWN8KB] Ground Fault of Detent Solenoid (Bucket)
Failure code [DWN8KY] Hot Short of Detent Solenoid (Bucket)
Failure code [DX19KA] Disconnection of Motor 1 Solenoid
Failure code [DX19KB] Ground Fault of Motor 1 Solenoid
Failure code [DX19KY] Hot Short of Motor 1 Solenoid
Failure code [DX20KA] Disconnection of Clutch Control Solenoid
Failure code [DX20KB] Ground Fault of Clutch Control Solenoid
Failure code [DX20KY] Hot Short of Clutch Control Solenoid
Failure code [DXAWKA] Disconnection of HST Pump EPC Sol
Failure code [DXAWKB] Ground Fault of HST Pump EPC Sol
Failure code [DXAWKY] Hot Short of HST Pump EPC Sol
Failure code [DXH7KA] Disconnection of Reverse Solenoid
Failure code [DXH7KB] Ground Fault of Reverse Solenoid
Failure code [DXH7KY] Hot Short of Reverse Solenoid
Failure code [DXH8KA] Disconnection of Forward Solenoid
Failure code [DXH8KB] Ground Fault of Forward Solenoid
Failure code [DXH8KY] Hot Short of Forward Solenoid
Failure code [DXHJKA] Disconnection of 3rd EPC Solenoid (EXT)
Failure code [DXHJKB] Ground Fault of 3rd EPC Solenoid (EXT)
Failure code [DXHJKY] Hot Short of 3rd EPC Solenoid (EXT)
Failure code [DXHKKA] Disconnection of 3rd EPC Solenoid (RET)
Failure code [DXHKKB] Ground Fault of 3rd EPC Solenoid (RET)
Failure code [DXHKKY] Hot Short of 3rd EPC Solenoid (RET)
Failure code [H2K0KA] Failure of Quick Coupler Lock Signal
Failure code [H2K0KY] Hot Short of Quick Coupler Lock Signal
Failure code [J141N1] Steering Pump Over Run
Failure code [LA00L3] Failure of Fan Reverse
Failure code [M100N1] HST Pump Over Run
Failure code [M400N1] HST Motor 1 Over Run
Troubleshooting of electrical system (E-mode)
E-1 Engine does not start
E-2 Manual preheating system does not work
E-3 Automatic preheating system does not work
E-4 While preheating is working, preheating monitor does not light up
E-5 All of LCD unit, LED unit, and meter unit on machine monitor display nothing
E-6 LCD unit on machine monitor displays nothing
E-7 Backlight of LCD unit on machine monitor is abnormal (Backlight goes out or flickers)
E-8 LCD on machine monitor does not display properly
E-9 Meter unit display on machine monitor is abnormal
E-10 Night lighting lamp of meter unit on machine monitor is abnormal
E-11 Caution LED on machine monitor is abnormal
E-12 LED of switch panel on machine monitor is abnormal or switches does not operate properly
E-13 Two switches operation of switch panel on machine monitor does not function
E-14 Switch panel buzzer of machine monitor is abnormal
E-15 Rearview monitor does not light up or backlight flickers
E-16 Rearview monitor images are not displayed clearly
E-17 Rearview monitor brightness cannot be adjusted
E-18 Night lighting lamp of rearview monitor is abnormal
E-19 Some items of gauges and caution lamps on machine monitor are not displayed properly
E-20 Parking brake indicator lamp does not light when the parking brake is set to ON (Parking) position
E-21 When brake accumulator oil pressure drops, the brake oil pressure caution lamp does not light
E-22 The HSToil filter clogging caution lamp does not light up
E-23 Radiator coolant level caution lamp does not light
E-24 Indication of HSToil temperature gauge does not increase, or HSToil temperature caution lamp does not light
E-25 When brake pedal (inching pedal) is depressed, inching function does not work (travel speed or traction force does not lower), or while not depressed, inching function operates
E-26 Fuel level gauge does not indicate correct level
E-27 Seat belt caution lamp indication is abnormal
E-28 Horn does not sound
E-29 Horn does not stop sounding
E-30 Alarm buzzer does not sound
E-31 When starting switch is in ON position, alarm buzzer does not stop sounding
E-32 When emergency HST pump drive switch is operated, emergency HST pump does not
work or when emergency HST pump drive switch is not operated, emergency HST
pump works
E-33 Setting does not change while operating traction control switch
E-34 Parking brake does not work even if it is applied, or the brake drags when parking brake
is released and FR drive is operated
E-35 Remote positioner does not work or cannot be released
E-36 Bucket positioner does not work or cannot be released
E-37 Direction selector (FNR) switch mode is not selected or not released
E-38 PZ auto tilt-in does not work
E-39 Tracktion level does not display MAX when max traction switch is turned ON
E-40 ECSS function cannot be selected or cannot be released
E-41 None of headlamp, clearance lamp, and tail lamp lights
E-42 Clearance lamp ,tail lamp and license plate lamp do not light up or go out
E-43 Both High and Low beams of headlamp do not light up or go out
E-44 Low beam of headlamp does not light up or go out
E-45 High beam of headlamp does not light up or go out
E-46 Front working lamp does not light up or go out
E-47 Rear working lamp does not light up or go out
E-48 All of turn signal lamps and hazard lamps do not flash or go out
E-49 Turn signal lamps do not flash or go out
E-50 Hazard lamp does not flash or go out
E-51 Brake lamp does not light or stays lighted
E-52 Backup lamp does not light up or does not go out
E-53 Backup buzzer does not sound or continues to sound
E-54 Front wiper does not operate
E-55 Rear wiper does not operate
E-56 Window washer does not operate
E-57 KOMTRAX system does not operate normally
Troubleshooting of hydraulic and mechanical system (H-mode)
Information described in troubleshooting table (H-mode)
System chart of hydraulic and mechanical systems
Failure mode and cause table
H-1 Machine does not travel forward or backward
H-2 Machine does not travel forward (Machine travels backward normally)
H-3 Machine does not travel backward (Machine travels forward normally)
H-4 Machine does not travel forward or backward fast
H-5 Machine does not travel forward fast (Machine travel backward fast)
H-6 Machine does not travel backward fast (Machine travel forward fast)
H-7 Machine lacks power neither when traveling forward nor backward
H-8 Machine lacks power when traveling forward (Machine has sufficient power when traveling backward)
H-9 Machine lacks power when traveling backward (Machine have sufficient power when traveling forward)
H-10 Engine stalls during travel or engine speed drops significantly
H-11 Steering wheel is too heavy to turn
H-12 Steering wheel is heavy to turn
H-13 Machine sways or large shocks are made while machine turns
H-14 Machine unintentionally turns when machine travels
H-15 Wheel brakes do not work or are weak
H-16 Wheel brakes are not released or drag
H-17 Parking brake does not work or it is weak
H-18 Parking brake is not released or drags
H-19 Boom does not rise
H-20 Boom moves slow or boom lacks lifting force
H-21 Rising boom slows down at certain height
H-22 Lift cylinders do not serve to hold bucket on ground (bucket rises off ground)
H-23 Hydraulic drift of boom is large
H-24 Boom moves up and down during operation
H-25 Bucket does not tilt back
H-26 Bucket moves slow or lacks tilt-back force
H-27 Bucket decelerates during tilt-back operation
H-28 Bucket cylinder does not hold bucket on ground
H-29 Hydraulic drift of bucket is large
H-30 Bucket tilts back and forth during carrying load (work equipment valve in HOLD)
H-31 Boom and bucket control levers do not move smoothly and are heavy to move
H-32 Operating work equipment causes engine speed to lower significantly or engine to stall
H-33 Large shocks are made when work equipment starts to move and stops
H-34 When certain work equipment is relieved hydraulically, other work equipment moves
H-35 E
H-36 Fan speed is abnormal (too high or low, or fan does not rotate)
H-37 Unusual noise is heard from around fan
Troubleshooting of engine (S-mode)
Information described in troubleshooting table (S mode)
S-1 Engine does not crank when starting switch is turned to START position
S-2 Engine cranks but no exhaust smoke comes out
S-3 Fuel is being injected but engine does not start (misfiring: engine cranks but does not start)
S-4 Engine startability is poor
S-5 Engine does not pick up smoothly
S-6 Engine stops during operation
S-7 Engine runs rough or is unstable
S-8 Engine lacks power
S-9 KDPF gets clogged in a short time
S-10 Engine oil consumption is excessive
S-11 Engine oil becomes contaminated early
S-12 Fuel consumption is excessive
S-13 Oil is in coolant (or coolant spurts or coolant level goes down)
S-14 Oil pressure drops
S-15 Fuel mixes into engine oil
S-16 Water mixes into engine oil (milky)
S-17 Coolant temperature rises too high (overheating)
S-18 Unusual noise is heard
S-19 Vibration is excessive
S-20 Air cannot be bled from fuel circuit
S-21 Active regeneration is executed frequently
S-22 Active regeneration takes time
S-23 White smoke is exhausted during active regeneration
50 Disassembly and assembly
Related information on disassembly and assembly
Coating materials list
Special tools list
Sketches of special tools
Engine and cooling system
Removal and installation of supply pump assembly
Removal and installation of injector assembly
Removal and installation of cylinder head assembly
Removal and installation of engine hood assembly
Removal and installation of grille assembly
Removal and installation of radiator core assembly
Removal and installation of aftercooler
Removal and installation of hydraulic oil cooler
Removal and installation of engine assembly
Removal and installation of engine front oil seal
Removal and installation of engine rear oil seal
Removal and installation of cooling fan and fan motor assembly
Removal and installation of KDPF assembly
Disassembly and assembly of KDPF assembly
Removal and installation of KCCV assembly
Removal and installation of air cleaner assembly
Removal and installation of KVGTassembly
Removal and installation of EGR (Exhaust Gas Recirculation) valve assembly
Removal and installation of EGR (Exhaust Gas Recirculation) cooler assembly
Removal and installation of alternator belt
Removal and installation of fuel tank assembly
Power train
Removal and installation of transfer assembly
Disassembly and assembly of transfer assembly
Disassembly and assembly of parking brake assembly
Disassembly and assembly of differential assembly
Removal and installation of front axle assembly
Removal and installation of rear axle assembly
Disassembly and assembly of axle housing assembly
Undercarriage and frame
Removal and installation of center hinge pin
Removal and installation of counterweight assembly
Hydraulic system
Removal and installation of hydraulic tank assembly
Removal and installation of control valve assembly
Disassembly and assembly of control valve assembly
Removal and installation of hydraulic pump assembly
Removal and installation of HST motor1 assembly
Removal and installation of HST motor2 assembly
Disassembly and assembly of hydraulic cylinder assembly
Work equipment
Removal and installation of work equipment assembly
Cab and its attachments
Removal and installation of operator’s cab and floor frame assembly
Removal and installation of operator’s cab glass (adhered glass)
Removal and installation of operator’s seat assembly
Removal and installation of seat belt
Electrical system
Removal and installation of machine monitor assembly
Removal and installation of engine controller assembly
Removal and installation of HSTcontroller assembly
Removal and installation of air conditioner controller assembly
Removal and installation of monitor controller assembly
Removal and installation of mass air flow and temperature sensor
Removal and installation of KOMTRAX terminal assembly
Air conditioner unit
Removal and installation of air conditioner compressor
Removal and installation of air conditioner condenser
Removal and installation of air conditioner unit assembly

60 Maintenance standard
Engine and cooling system
Engine related parts
Cooling fan motor
Power train
Damper
Transfer
Drive shaft
Axle
Differential
Limited slip differential
Final drive
Steering system
Steering column
Priority valve
Emergency steering valve
Steering cylinder
Brake system
Brake accumulator charge valve
Slack adjuster
Brake
Parking brake
Parking brake solenoid valve
Undercarriage and frame
Axle mount
Center hinge pin
Hydraulic system
Hydraulic tank
Double type gear pump
Steering and work equipment pump
Control valve
Self-pressure reducing valve
Work equipment PPC valve
Work equipment lock solenoid valve
Work equipment
Index
Work equipment linkage
Bucket
Work equipment cylinder
Cab and its attachments
Cab mount
Electrical system
Bucket positioner
Fork positioner
Remote boom positioner

Appendix
Table of contents
Air conditioner components
Precautions for refrigerant
Air conditioner component
Configuration and function of refrigeration cycle
Outline of refrigeration cycle
Air conditioner unit
Dual pressure switch
Air conditioner controller
Compressor
Condenser
Receiver drier
Sunlight sensor
Outer temperature sensor (outside air temperature sensor)
Procedure for testing and troubleshooting
Circuit diagram and arrangement of connector pins
System diagram
Parts and connectors layout
Testing with self-diagnosis function
How to open the electrical system abnormality record screen in service mode of the machine monitor
Testing temperature control system
Testing vent (mode) changeover
Testing FRESH/RECIRC air changeover
Testing evaporator temperature sensor
Testing relays
Troubleshooting chart 1
Troubleshooting chart 2
Information in troubleshooting table
Failure code list related to air conditioner
Failure code [879AKA] A/C Inner Sensor Open Circuit
Failure code [879AKB] A/C Inner Sensor Short Circuit
Failure code [879BKA] A/C Outer Sensor Open Circuit
Failure code [879BKB] A/C Outer Sensor Short Circuit
Failure code [879CKA] Ventilating Sensor Open Circuit
Failure code [879CKB] Ventilating Sensor Short Circuit
Failure code [879DKZ] Sunlight Sensor Open or Short Circuit
Failure code [879EMC] Ventilation Damper Abnormality
Failure code [879FMC] Air Mix Damper Abnormality
A-1 Troubleshooting for power supply and CAN communication system (Air conditioner does not operate)
A-2 Troubleshooting for compressor and refrigerant system (Air is not cooled)
A-3 Troubleshooting for blower motor system (No air comes out or air flow is abnormal)
A-4 Troubleshooting for FRESH/RECIRC air changeover
Troubleshooting with gauge pressure
Connection of service tool
Precautions for disconnecting and connecting hoses and tubes in air conditioner circuit
Index
Handling of compressor oil

Diagrams and drawings
Hydraulic circuit diagram
Symbols in hydraulic circuit diagram
Hydraulic circuit diagram
Electric circuit diagram
Symbols in electric circuit diagram
Electrical circuit diagram of machine body
Electrical circuit diagram of floor
Index

Covers: Komatsu WA270-7 Wheel Loader (USA, Serial No. A27001 and up)
Pages: 2,048
Format: PDF
Compatibility: Windows/Mac/Tablet
File size: 56mb
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