SPN 2791 FMI 14EGR
EGR Valve Position - Special Instructions
Scan Tool — in guided session
DVOM Testing — in guided session
Connector Pinout — in guided session
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Overview
Fault Code
SPN 2791 / FMI 14
Category
EGR
Derate Risk
No
Regen Inhibit
No
Inducement Risk
No
Component Location: EGR valve is typically mounted on the intake manifold or EGR cooler outlet on the engine, accessible from the top or side of the engine block.
Common Symptoms
- Check engine light illuminated
- EGR valve fault code active
- Engine derate or reduced power
- Poor throttle response
- Black smoke under load
- Increased NOx emissions
- EGR valve position not responding to commanded position
Root Causes
- EGR valve stuck open or closed due to carbon buildup
- EGR valve actuator failure or degraded performance
- EGR valve position sensor out of range or erratic signal
- EGR cooler restriction causing reduced flow and position error
- Wiring harness chafing or connector corrosion at EGR valve
- ECM detected EGR valve unable to achieve commanded position within tolerance
- Intake or exhaust passage restriction affecting EGR delta pressure
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Derate Behavior
Power Derate
No
Mileage / Regen Notes
SPN 2791 FMI 14 may inhibit or limit active DPF regeneration because proper EGR control is required for exhaust temperature management; if the EGR valve cannot be commanded to a safe position, the ECM may derate the engine and block regen events to protect the aftertreatment system.
System Interactions
SPN 2791 FMI 14 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
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Related Diagnostic Articles
Deep-dive diagnostic page: SPN 2791 FMI 14 — 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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