Aftertreatment SCR Inlet Temperature - Voltage Above Normal or Shorted to High Source
The JD-SPN4360-FMI3 (John Deere PowerTech) diesel fault code means: Aftertreatment SCR Inlet Temperature - Voltage Above Normal or Shorted to High 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 NOx sensor / SCR temp sensor, $3,500-$7,500 SCR catalyst
What Are the Symptoms of JD-SPN4360-FMI3?
- SCR NOx-efficiency fault, derate within one drive cycle if persistent
- Low tailpipe NOx conversion at operating temp
- Dealer-inducement warnings on Tier 4 Final machines
What Causes JD-SPN4360-FMI3? (Most Likely First)
- Upstream / downstream NOx sensor drift Likely
- SCR inlet / outlet temperature sensor failure Likely
- SCR substrate poisoning (wrong DEF) or thermal damage Possible
- Exhaust leak upstream of SCR disturbing sensor reading Possible
Can I Still Drive with JD-SPN4360-FMI3?
Reduced power (derate). JD-SPN4360-FMI3 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 4360 FMI 3?
On John Deere PowerTech engines, SPN 4360 FMI 3 means: Aftertreatment SCR Inlet Temperature - Voltage Above Normal or Shorted to High Source. Moderate code -- diagnose soon; continued operation may increase repair scope.
Can I keep using my John Deere tractor with SPN 4360 FMI 3?
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 4360 FMI 3?
Repair cost range: $260-$780 NOx sensor / SCR temp sensor, $3,500-$7,500 SCR catalyst. Dealer labor on large tractors runs $180-$240/hr in 2026.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose JD-SPN4360-FMI3?
Record SCR inlet vs. outlet temperature during steady-state high idle.
Use Service ADVISOR SCR efficiency test -- compare to CTM acceptance band.
Inspect clamps / V-bands between turbo and SCR for leaks.
If substrate is damaged, only a full catalyst module replacement will clear the code.
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-SPN4360-FMI3?
- 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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