John Deere 644K 4WD Loader 6068HDW80, 6068HDW83 Operation and Test Technical Manual (TM10694)

John Deere 644K 4WD Loader Engine 6068HDW80 (T3), 6068HDW83 (S2) Operation and Test Technical Manual (TM10694 19DEC18)

This in-depth technical manual provides detailed diagnostics, operational checks, and testing instructions for the John Deere 644K 4WD Loader equipped with either the 6068HDW80 (Tier 3) or 6068HDW83 (Stage II) engines. It is an essential guide for professional technicians working with advanced electronic systems, CAN diagnostics, hydraulic systems, transmission calibration, HVAC operation, and safety protocols.

Model Covers:

644K 4WD Loader
Engine: 6068HDW80 (T3), 6068HDW83 (S2)
Serial Number: –642443

File Format: PDF

Size: 42.28 MB

No. of pages: 1332

Language: English

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

📑 Included Sections:

Safety and General Information

• Extensive safety warnings and worksite precautions
• Protective equipment guidelines and emergency preparedness
• Fire prevention, high-pressure fluid safety, battery explosion prevention

Diagnostic Trouble Codes (DTCs)

• Complete ECU, TCU, FLC, SSM, ADU, JSC, and TPM code references
• Code explanations and step-by-step fault isolation procedures
• Coverage includes solenoids, sensors, relays, voltage errors, CAN communication faults

Engine and Performance Systems

• 6068HDW80 (Tier 3) and 6068HDW83 (Stage II) engine testing procedures
• Startup, idle, fuel system, turbocharger boost, and excessive smoke diagnostics
• Cooling system checks, air filter restrictions, fast-fill diagnostics

Electrical System and CAN Network

• Full wiring diagrams and component location maps
• CAN network diagnostics and controller communication checks
• Advanced Display Unit (ADU) operations, JDLink™, service advisor connections

Powertrain and Transmission

• Torque converter operation and lockup clutch diagnostics
• Clutch calibration, oil pressure/flow tests, park brake adjustments
• Drive shaft and differential lock troubleshooting

Hydraulic System

• Main pump operation, valve pressure settings, cylinder diagnostics
• Ride control, pilot control levers, and accumulator procedures
• Fan and steering hydraulic systems – normal, reversing, and secondary

Heating and Air Conditioning

• Air conditioning cycle, refrigerant pressure testing, and leak checks
• Compressor diagnostics, freeze switch operation, HVAC control faults
• Cab climate system optimization and airflow diagnostics

This John Deere 644K Loader Operation and Test Technical Manual is a vital resource for skilled technicians, offering complete system diagnostics, calibration steps, and repair instructions for maintaining peak loader performance.