2006–2011 Honda TRX680FA / TRX680FGA ATV Service & Repair Manual

This Honda service manual covers the 2006–2011 TRX680FA and TRX680FGA ATVs, including GPS-equipped models, with maintenance, system diagnosis, and mechanical repair procedures.

Text Search, Bookmarks, and Wiring Detail

Search and diagram limitations: An embedded OCR layer supports searches across many service sections, but recognition errors limit exact matches and the contents page is not searchable. The PDF has bookmarks for all 26 numbered sections. Small pin and wire-color labels in the full wiring diagram remain partly blurred when enlarged.

Supplied as one printable, English-language, 567-page PDF, including one additional cover page already counted in the total.

Engine, Automatic Transmission, and Chassis Service

These selected service topics outline the main coverage; the manual also contains recoil-starter repair and bank-angle-sensor testing.

• Maintenance: Scheduled service, valve-clearance adjustment, fluid and filter changes, and inspections of brakes, steering, suspension, and drive-shaft boots.

• Engine repair: Engine removal and installation, compression testing, cylinder-head and piston inspection, valve-guide replacement, valve-seat refacing, and crankcase, crankshaft, and balancer service.

• PGM-FI diagnostics: Trouble-code retrieval and clearing, sensor-circuit checks, fuel-pressure and flow tests, throttle-body service, and idle-air-control-valve inspection.

• Transmission and selectable 4WD: Hydraulic pressure testing, shift-valve-body service, shift-clutch/mainshaft disassembly, and electrical diagnosis of the front final clutch.

• Final drives and chassis: Differential and rear final-drive repair, gear backlash and contact-pattern checks, suspension and steering service, and hydraulic brake bleeding.

• Electrical systems: Wiring diagrams, charging and ignition tests, starter-motor repair, combination-meter checks, and GPS-receiver troubleshooting.

The manual is intended for qualified professional technicians with service training, appropriate tools, and workshop equipment.

PGM-FI and Drivetrain Fault Diagnosis

The PCM combines engine and transmission control, and some sensor faults affect both systems. The manual explains how PGM-FI codes, gear-position-indicator codes, and selectable-4WD faults relate, rather than treating each warning as an isolated problem.

Step-by-step procedures cover PGM-FI code retrieval and clearing with SCS connector 070PZ-ZY30100, alongside HDS Pocket Tester diagnosis. Throttle-body service is limited to the specified disassembly; disturbing factory-painted adjustment fasteners can cause malfunction.

For transmission complaints, line- and shift-clutch-pressure tests are paired with a hydraulic-circuit troubleshooting chart. These references help technicians distinguish hydraulic supply problems from clutch, solenoid, or sensor faults before choosing a teardown.

The emergency-valve section explains its use when the clutch-pressure-control solenoid is mechanically stuck. It also describes the resulting fixed-gear operation and creeping at idle. Engine oil supplies the A/T hydraulic circuit; the lubrication specifications call for oil without molybdenum additives.

Engine Repair, Lubrication, and Cooling

The engine sections provide step-by-step instructions for internal inspection and reassembly, including rocker-arm, camshaft, valve, cylinder, and piston work. Cylinder-head-cover installation carries a specific warning: tightening the cover with the rocker arms misaligned with the pushrod ends can cause severe engine damage.

Oil-pump inspection and oil-cooler service are supported by the lubrication-system diagram. Cooling coverage includes radiator-cap and system pressure tests, thermostat inspection, coolant replacement and air bleeding, and water-pump mechanical-seal replacement.

Transmission Access and Final-Drive Work

The torque converter and first shift clutch can be serviced with the engine installed. Mainshaft and second/third shift-clutch work requires engine removal and crankcase separation. Torque-converter inspection is included, with a faulty converter replaced as an assembly.

The sub-transmission section covers selector linkage and cable adjustment. Front and rear driving-mechanism sections add bearing replacement, shim selection, and gear-tooth contact-pattern illustrations for differential and final-drive work.

Brakes, Steering, and Electrical Reference

Brake coverage extends to master-cylinder and caliper disassembly and inspection. Steering and suspension sections address wheel hubs, knuckles, arms, ball joints, and toe adjustment; frame/body-panel and exhaust procedures cover access and removal.

Electrical references include the PGM-FI System Diagram, Drivetrain System Diagram, charging-system schematic, and cable/harness-routing views. Ignition timing is covered as an inspection; the PCM-controlled timing is factory preset and cannot be adjusted. GPS diagnosis addresses communication errors and delayed startup.

Engine removal and brake work require secure vehicle support and the manual’s handling and service precautions.

Sample Valve-Clearance, Torque, and Refill Data

Valve-clearance specifications are 0.15 mm intake and 0.33 mm exhaust with the engine cold, below 35°C. The rear final gear-case refill after draining is 78 cm³; the manual lists a separate capacity after disassembly.

Torque examples include 55 N·m for the cylinder-head-cover cap nut and 108 N·m for the primary driven-gear lock nut, with the specified engine-oil application and fastening notes.