SPN 412 FMI 7EGR
EGR Valve Position - Mechanical System Not Responding
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Overview
Fault Code
SPN 412 / FMI 7
Category
EGR
Derate Risk
Yes
Regen Inhibit
No
Inducement Risk
No
Component Location: EGR valve is mounted on the EGR cooler outlet at the intake manifold side of the engine, typically on the left or right side of the engine block depending on the ISX/X15 platform variant.
Common Symptoms
- Check engine light illuminated
- Engine derate or reduced power
- Poor acceleration response
- Increased exhaust smoke
- Rough idle or unstable engine operation
- Elevated NOx emissions
Root Causes
- EGR valve stuck open or closed due to carbon/soot buildup on valve stem and seat EGR valve actuator motor failure or binding EGR cooler restriction causing insufficient flow and position mismatch EGR valve position sensor (feedback potentiometer) failure Excessive carbon deposits in EGR valve bore preventing mechanical movement Damaged or worn EGR valve return spring EGR differential pressure sensor fault causing incorrect commanded position Wiring harness chafing or connector damage at EGR valve assembly EGR valve stuck due to thermal distortion or warped housing
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Derate Behavior
Power Derate
Yes
Mileage / Regen Notes
SPN 412 FMI 7 may inhibit or severely restrict active DPF regeneration. EGR mechanical non-response disrupts combustion air management, which can cause the ECM to delay or abort regen events to protect the aftertreatment system. Parked regen may be blocked until the fault is resolved. Engine may enter derate mode depending on calibration.
System Interactions
SPN 412 FMI 7 interacts with the following systems and may trigger cascading faults if not resolved promptly.
Common Diagnostic Mistakes
Replacing the sensor without verifying wiring continuity and supply voltage first.
Clearing codes without identifying and resolving the root cause — the fault will return.
Ignoring related active faults — cascading faults often share a root cause.
Skipping the connector inspection — corrosion and damaged pins are a leading cause of sensor faults.
Condemning the ECM before exhausting all wiring and component tests.
Related Faults in This Category
OEM System Resources
ASE Training Resources
Diagnostic Engine v7.0
Related Diagnostic Articles
Deep-dive diagnostic page: SPN 412 FMI 7 — Full FSM Sequence & Repair Steps — includes wiring notes, sensor specs, and gated repair procedures.
Authority References
Diagnostic procedures on this page are informed by OEM service literature and industry standards.
Cummins QuickServe OnlineOfficial Cummins service manuals, fault code lookup, and TSB database.Detroit Diesel DiagnoCentralDetroit Diesel diagnostic procedures, DDDL documentation, and service literature.PACCAR MX Engine ServicePACCAR MX-11 and MX-13 engine service documentation and DAVIE diagnostic guides.Volvo/Mack Tech ToolVolvo and Mack engine fault code reference and PTT/Tech Tool diagnostic procedures.ASE — Diesel Truck Technician CertificationNational Institute for Automotive Service Excellence — T2 Diesel Engines certification standards.EPA Aftertreatment & Emissions GuidelinesU.S. EPA heavy-duty diesel aftertreatment compliance, DPF/SCR regulations, and NOx standards.
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