Aftertreatment DOC Intake Temperature - Voltage Below Normal or Shorted to Low Source
The JD-SPN4765-FMI4 (John Deere PowerTech) diesel fault code means: Aftertreatment DOC Intake Temperature - Voltage Below Normal or Shorted to Low Source. This is a moderate severity code.
Unverified. We could not confirm this code's definition against freely available manufacturer documentation, so treat the meaning, severity and fix guidance on this page as unconfirmed. Check it against the manufacturer's service information for your exact model and serial range before acting on it. This page is kept out of search engines for that reason, and we are working through this family manual by manual.
- Keep driving?
- Reduced power (derate)
- DIY difficulty
- advanced
- Estimated cost
- $260-$780 DOC temp sensor, $2,800-$6,000 DOC replacement
What Are the Symptoms of JD-SPN4765-FMI4?
- Active regen failure or abnormally long regen time
- DOC temperature sensor fault on operator display
- Elevated tailpipe HC / CO emissions
What Causes JD-SPN4765-FMI4? (Most Likely First)
- DOC inlet / outlet temp sensor failure Likely
- Soot contamination on thermocouple tip Likely
- DOC face plugged by unburnt fuel from injector leak Possible
- HC doser / 7th injector soot build-up on the upstream side Possible
Can I Still Drive with JD-SPN4765-FMI4?
Reduced power (derate). JD-SPN4765-FMI4 is rated moderate severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.
Frequently Asked Questions
What is John Deere fault code SPN 4765 FMI 4?
On John Deere PowerTech engines, SPN 4765 FMI 4 means: Aftertreatment DOC Intake Temperature - Voltage Below Normal or Shorted to Low Source. Moderate code -- diagnose soon; continued operation may increase repair scope.
Can I keep using my John Deere tractor with SPN 4765 FMI 4?
Moderate fault -- you can usually keep working but expect derate if aftertreatment-related. Diagnose with John Deere Service ADVISOR via an EDL v3 / CF3 interface.
How much does it cost to fix John Deere SPN 4765 FMI 4?
Repair cost range: $260-$780 DOC temp sensor, $2,800-$6,000 DOC replacement. Dealer labor on large tractors runs $180-$240/hr in 2026.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose JD-SPN4765-FMI4?
Watch DOC inlet vs. outlet Δ during active regen -- should rise >100 °C.
Inspect DOC substrate for melt / glazing -- requires replacement.
Clean or replace the DOC temperature sensor harness and thermocouple.
Inspect HC doser or 7th injector fuel pattern.
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- SAE J1939-73Application Layer: Diagnostics (defines the SPN/FMI fault-identifier framework)
Which Vehicles Commonly Get JD-SPN4765-FMI4?
- 2015+ John Deere 7R Series (7210R, 7250R, 7290R, 7310R)
- 2015+ John Deere 8R / 8RT Series (8245R-8370R)
- John Deere S670 / S680 / S690 combines
- John Deere S770 / S780 / S790 combines
- 2021+ John Deere X9 1000 combine
- John Deere 1025R sub-compact utility tractor
- John Deere 2025R / 2038R / 2032R compact utility tractors
- John Deere R4045 / R4060 self-propelled sprayers
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