SPN 3700 FMI 31 — DPF active regeneration in progress
What it means: DPF active regeneration in progress.
How serious / can you keep driving: Informational. Usually OK to continue — monitor closely.
Check first: Let regen complete (15-40 min typical)
Don't risk it — look up listed providers near you and give them this SPN/FMI when you call.
Listed providers nearest Billings, MT
Closest first. Tell them SPN 3700 FMI 31 and what the truck is doing. RoadService.app lists these providers and does not employ them or carry out the repair.
- 0.0 mi away — based in Billings, MT · (406) 245-8985
- 0.0 mi away — based in Billings, MT · (406) 252-8413
- 0.0 mi away — based in Billings, MT · (406) 780-3711
Applies to: Sae · Not a fault
What SPN 3700 FMI 31 means
DPF active regeneration in progress.
How serious is it?
Informational. Usually OK to continue — monitor closely.
Most likely causes
- Normal operation — no action
First moves (roadside)
- Let regen complete (15-40 min typical)
Common misdiagnoses
- Clearing the code
FAQ
DPF active regeneration in progress.
Informational — Usually OK to continue — monitor closely.
The most common cause is: Normal operation — no action.
Usually OK to continue — monitor closely. When in doubt, get a qualified mobile diesel tech on the truck before continuing.
Related codes
Codes that commonly appear alongside SPN 3700 FMI 31, or share the same subsystem.
- SCR Operator Inducement — Severe Derate Active (SPN 5246 FMI 0)
- Aftertreatment 1 Diesel Particulate Filter Differential Pressure - Data Valid But Above Normal Operating Range, Most Severe Level (DPF severely restricted / plugged) (SPN 3251 FMI 0)
- Aftertreatment 1 Diesel Exhaust Fluid Quality - Data Valid But Below Normal Operating Range, Most Severe Level (DEF quality/concentration incorrect) (SPN 4364 FMI 1)
- DPF Differential Pressure — Data Erratic (SPN 3251 FMI 2)
- DEF Dosing Unit — Not Responding Properly (SPN 3361 FMI 7)
- SCR Conversion Efficiency — Below Threshold (SPN 4364 FMI 18)
- DEF Quality — Out of Spec (SPN 4094 FMI 31)
- EGR Temperature — Too High (SPN 412 FMI 0)
Same symptom: Regen problems
Other codes that block a regen or come back as soot load climbing.
- DPF Soot Accumulation Restriction (P2460) · Aftertreatment & Emissions
- DPF inlet temp sensor — voltage high (SPN 3241 FMI 3) · Aftertreatment & Emissions
- DPF outlet temp erratic (SPN 3242 FMI 2) · Aftertreatment & Emissions
- DPF outlet temp sensor — voltage high (SPN 3246 FMI 3) · Aftertreatment & Emissions
- DPF differential pressure — voltage high (SPN 3251 FMI 3) · Aftertreatment & Emissions
- DPF differential pressure — voltage low (SPN 3251 FMI 4) · Aftertreatment & Emissions
Find a mechanic or related guides
General diagnostic guidance for heavy-duty diesel engines (Cummins, Detroit, PACCAR, Volvo, Mack). Not a substitute for a scan-tool diagnosis on your specific truck.