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SPN 3703 FMI 31 — DPF regeneration inhibited
InformationalAftertreatmentUsually OK to continue — monitor closely
Applies to: Sae
DPF regeneration inhibited.
Don't risk it — get a diesel tech on the truck.
Your SPN/FMI rides along, so nearby mechanics see the fault before they quote you.
How serious is it?
Informational. Usually OK to continue — monitor closely.
Most likely causes
- Driver-inhibited via switch
- Operating condition preventing regen
First moves (roadside)
- Check inhibit switch position
Common misdiagnoses
- Replacing the switch
FAQ
What does SPN 3703 FMI 31 mean?
DPF regeneration inhibited.
How serious is SPN 3703 FMI 31?
Informational — Usually OK to continue — monitor closely.
What's the most likely cause of SPN 3703 FMI 31?
The most common cause is: Driver-inhibited via switch. Other possibilities include Operating condition preventing regen.
Can I keep driving with SPN 3703 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.