SPN 412 FMI 16EGR
EGR System - Data Valid But Above Normal
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Overview
Fault Code
SPN 412 / FMI 16
Category
EGR
Derate Risk
Yes
Regen Inhibit
No
Inducement Risk
No
Component Location: EGR valve is mounted on the intake manifold with the EGR cooler positioned in the exhaust gas recirculation circuit.
Common Symptoms
- Active fault code with MIL illuminated
- Elevated exhaust temperatures
- Reduced engine power or derate
- Increased NOx emissions
- Rough idle or poor throttle response
- Failed emissions test
- Excessive black smoke from exhaust
Root Causes
- EGR valve stuck open or not closing fully
- EGR cooler fouling or restriction reducing flow control
- Carbon buildup in EGR passages causing incorrect valve position feedback
- Faulty EGR valve position sensor reporting incorrect data
- EGR differential pressure sensor failure or drift
- Intake manifold pressure sensor out of calibration
- Leaking EGR cooler causing excess recirculation
- ECM calibration or software issue misinterpreting EGR feedback
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Derate Behavior
Power Derate
Yes
Mileage / Regen Notes
SPN 412 FMI 16 can inhibit or delay active DPF regeneration due to abnormal EGR flow affecting combustion efficiency and exhaust temperature targets; ECM may require EGR fault resolution before enabling regen.
System Interactions
SPN 412 FMI 16 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 16 — 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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