John Deere 644K 4WD Loader Engine 6090HDW13 Operation and Test Technical Manual (TM12105)

John Deere 644K 4WD Loader Engine 6090HDW13 Operation and Test Technical Manual (TM12105 13DEC11)

This official John Deere technical manual provides comprehensive diagnostic procedures, system operation theory, and testing instructions for the 644K 4WD Loader equipped with engine model 6090HDW13. Designed for professional service technicians, it includes detailed guidance on fault codes, controller diagnostics, electrical schematics, hydraulic testing, powertrain evaluation, and ADU service menus for ensuring peak performance.

Model Covers:

644K 4WD Loader
Engine: 6090HDW13
Serial Number: 634315 –

File Format: PDF

Size: 38.20 MB

No. of pages: 1372

Language: English

Delivery Method: Instant Download – Access your file immediately after purchase.

📑 Included Sections:

Safety and General Information

• Operator safety guidelines and emergency protocols
• Battery handling, high-pressure fluids, and fire hazard precautions
• ROPS inspection, attachment usage, slope operation safety

Diagnostic Trouble Codes (DTCs)

• Full coverage of ECU, TCU, VCU, SSM, ADU, TPM, JSV, and JSC codes
• Step-by-step diagnostic procedures for electrical, hydraulic, and communication faults
• CAN communication errors, engine misfire, clutch calibration faults, and more

Engine and Electrical Systems

• Engine 6090HDW13 diagnostics and operational theory
• Cold start aid, fast fill fuel system, intake/exhaust components
• Wiring schematics, connector testing, and service ADVISOR™ integration

Powertrain System

• TeamMate™ axle diagnostics, torque converter testing
• Transmission oil pressure tests, clutch pack engagement, calibration routines
• Service and park brake pressure testing and adjustments

Hydraulic System

• Main pump and load sense circuit operation and diagnostics
• Joystick steering and pilot control theory
• Fan and auxiliary hydraulic systems, accumulator testing

Heating, Air Conditioning, and Monitor Operation

• Compressor, freeze switch, and HVAC system diagnostics
• ADU service mode: fault code clearing, calibration, and feature configuration
• Tire Pressure Monitoring System (TPM), JDLink™, and optional attachments setup

For complete service information, also see:

644K Loader Repair Manual .......... TM12107
644K Loader Operator's Manual .......... OMT260553
9.0L OEM Diesel Engines — Interim Tier 4/Stage III B platform .......... CTM104819
TeamMate™ IV 1200–1400 Series Inboard Planetary Axles .......... CTM442
120 Series Hydraulic Cylinders .......... CTM114319
185 Series Hydraulic Cylinders .......... CTM114919
JDLink™ (MTG) Diagnosis and Tests Manual .......... TM114519
Specifications Manual .......... SP458

This John Deere 644K Loader Technical Manual is the definitive guide for diagnostics, electronic and hydraulic testing, and operational verification, empowering technicians to maintain the loader at peak efficiency.