Home › Fault codes › SPN 3700 FMI 31
SPN 3700 FMI 31 — DPF active regeneration in progress
InformationalAftertreatmentUsually OK to continue — monitor closely
Applies to: Sae · Not a fault
DPF active regeneration in progress.
Don't risk it — get a diesel tech on the truck.
Look up listed providers near you and give them this SPN/FMI when you call.
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
What does SPN 3700 FMI 31 mean?
DPF active regeneration in progress.
How serious is SPN 3700 FMI 31?
Informational — Usually OK to continue — monitor closely.
What's the most likely cause of SPN 3700 FMI 31?
The most common cause is: Normal operation — no action.
Can I keep driving with SPN 3700 FMI 31?
Usually OK to continue — monitor closely. When in doubt, get a qualified mobile diesel tech on the truck before continuing.
Throwing this code right now?
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.