John Deere 9120, 9220, 9320, 9420, 9520 and 9620 Tractors Diagnosis and Tests Manual (TM1972)

What's Covered in This Manual

This is the Diagnosis and Tests Manual (TM1972, dated January 2013) covering six John Deere 4WD Articulated Tractors: the 9120, 9220, 9320, 9420, 9520 and 9620. Engine coverage splits cleanly by model size: the 9120, the smallest of the six, runs the PowerTech 8.1L diesel (referenced to CTM255), while the 9220 through 9620 step up to the larger PowerTech 10.5L or 12.5L diesel engines (referenced to CTM86 and CTM100), reflecting the jump in horsepower across this flagship articulated tractor line.

The manual's Service Codes section is organized by controller abbreviation rather than by system - ACU, AMS, ASU, ATC, CCU, ECU, HCU, ICU, JDL, PCU, and several others - which matters because these tractors carry a genuinely complex electronic architecture spanning the hitch and SCV controls (ACU), Ag Management Solutions (AMS), the automatic track/articulation system (ASU), and the CLIMATRAK automatic temperature control (ATC), among others. Knowing which controller a fault code belongs to is the first step in correctly diagnosing one of these tractors.

Beyond fault codes, the manual's Observable Symptoms and System Diagnosis sections cover axles, electrical, the hitch, heating/ventilation/air conditioning (with separate procedures for tractors built before and after serial number 010001 on the CLIMATRAK system), the operator station, PowerShift and Manual Shift transmissions, power take-off, selective control valves, and both standard steering and the AutoTrac automated steering system. Hydraulic system diagnostics are also split three ways - Standard, Scraper High Flow, and Ag High Flow - since the hydraulic circuit differs depending on which configuration the tractor was built with. For anyone troubleshooting one of these six articulated tractors, this manual gives the complete diagnostic path across every one of these systems.

Table of Contents

• Section 210 - General - safety, general specifications and references
• Section 211 - Service Codes - fault codes by controller - ACU, AMS, ASU, ATC, CCU, ECU, HCU, ICU, JDL, PCU and more
• Section 212 - Observable Symptoms - axles, electrical, hitch, HVAC, operator station, transmission, PTO, steering
• Section 213 - System Diagnosis - PowerShift and Manual Shift transmission, steering, AutoTrac, hydraulic system
• Section 220 - Engine - operational checks, tests and adjustments, theory of operation
• Section 230 - Fuel and Air - fuel system diagnostics