John Deere 8120, 8220, 8320, 8420 and 8520 Tractors Diagnostics and Test Manual (TM1980)

TM1980 is the diagnostic manual for the 8020 Series, built around service codes. If your tractor shows an ACU code for the hitch, SCVs or the shift lever, each code has its own procedure here. Nothing is lumped into a generic hydraulic fault.

Fits

8120, 8220, 8320, 8420 and 8520 with PowerTech 8.1L and Level 9 electronic fuel injection (CTM255).

What this manual covers

The general section covers more than thirty safety topics plus practical electrical skills: reading schematics, using a probe light, telling electrical from electronic faults, and tracking down intermittents. ACU service codes cover SCV lever calibration, throttle, hitch raise and lower, rate-of-drop, IMS switch, transmission shift lever and auto-resume faults. Fuel system codes point to CTM255 for the underlying procedure. Wiring diagrams and schematic symbol references round it out. This is the manual to have when the tractor is in the field and a code comes up; it tells you exactly what the code means and what to check first.

Table of contents

• Section 210 - General - safety information, general reference list, electrical troubleshooting fundamentals
• Section 211 - Service Codes - ACU - SCV, throttle, hitch and transmission lever fault codes
• Engine Fuel System Diagnostics - PowerTech 8.1L Level 9 electronic fuel system fault codes
• Electrical Reference Material - wiring diagrams, schematic symbols, probe light and multimeter use

Check before you buy

Diagnostics only. Fuel system service needs CTM255, sold separately.

PDF, English. You get the download link right after checkout. Sold by an independent seller, not affiliated with or endorsed by John Deere.