Aftertreatment DPF Ash Load Percent - Data Valid but Above Normal Operational Range (Least Severe)
What does JD-SPN3720-FMI15 mean?
The JD-SPN3720-FMI15 (John Deere PowerTech) diesel fault code means: Aftertreatment DPF Ash Load Percent - Data Valid but Above Normal Operational Range (Least Severe). This is a minor severity code.
Common Symptoms
- Frequent passive regen never completes (short-duty tractors)
- DPF lamp + derate on soot load > 100%
- Parked regen request every few hours
Probable Causes (Ranked by Likelihood)
- Short-duty-cycle use stopping passive regen from occurring Very Likely
- Differential pressure sensor hose plugged / cracked Likely
- Ash loaded beyond service interval (5,000+ hrs) Likely
- DPF substrate cracked from over-temp regen Possible
Step-by-Step Diagnostic Procedure
Record DPF ΔP and soot load in Service ADVISOR at rated load.
Command parked regen and monitor DPF inlet temperature ramp.
Clean DPF differential pressure sensor hoses (common on compact tractors).
If ash load > 95%, remove and send out for ash cleaning.
Frequently Asked Questions
What is John Deere fault code SPN 3720 FMI 15?
On John Deere PowerTech engines, SPN 3720 FMI 15 means: Aftertreatment DPF Ash Load Percent - Data Valid but Above Normal Operational Range (Least Severe). Minor code -- monitor; does not affect safe operation.
Can I keep using my John Deere tractor with SPN 3720 FMI 15?
Minor fault -- finish the job, then service at the next opportunity. Diagnose with John Deere Service ADVISOR via an EDL v3 / CF3 interface.
How much does it cost to fix John Deere SPN 3720 FMI 15?
Repair cost range: $450-$1,200 differential pressure sensor, $1,800-$4,500 DPF clean / replace. Dealer labor on large tractors runs $180-$240/hr in 2026.