Home › Fault codes › SPN 3712 FMI 18
SPN 3712 FMI 18 — SCR inducement — stage 3 (severe derate)
CautionAftertreatmentLimp to the next safe stop
Applies to: Detroit · Sae · The dreaded 5 MPH limp
SCR inducement — stage 3 (severe derate).
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?
Caution. Limp to the next safe stop.
Most likely causes
- Parent fault unaddressed — final stage
- Parent SCR fault unaddressed
First moves (roadside)
- Fix parent
- Clear via OEM tool
- Clear via DiagnosticLink
FAQ
What does SPN 3712 FMI 18 mean?
SCR inducement — stage 3 (severe derate).
How serious is SPN 3712 FMI 18?
Caution — Limp to the next safe stop.
What's the most likely cause of SPN 3712 FMI 18?
The most common cause is: Parent fault unaddressed — final stage. Other possibilities include Parent SCR fault unaddressed.
Can I keep driving with SPN 3712 FMI 18?
Limp to the next safe stop. 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.