SPN 411 FMI 0EGR
EGR Temperature Sensor A Circuit Intermittent
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Connector Pinout — in guided session
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Overview
Fault Code
SPN 411 / FMI 0
Category
EGR
Derate Risk
No
Regen Inhibit
No
Inducement Risk
No
Component Location: EGR temperature sensor is mounted directly on the EGR valve assembly or EGR cooler outlet pipe, typically on the intake side of the engine.
Common Symptoms
- Check engine light illuminated
- Engine derate or reduced power
- Poor fuel economy
- Increased exhaust smoke
- Rough engine operation during EGR valve cycling
- Intermittent fault code that may come and go
Root Causes
- Intermittent open or high resistance in EGR temperature sensor signal or return wiring harness Corroded, spread, or loose connector pins at EGR temperature sensor harness connector Failed or degrading EGR temperature sensor (thermistor element drifting out of range) Chafed or damaged wiring harness causing intermittent short or open circuit ECM connector pin corrosion or poor contact causing intermittent signal dropout Excessive heat damage to sensor wiring near EGR cooler or exhaust components Moisture intrusion into sensor connector causing intermittent resistance shifts
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Derate Behavior
Power Derate
No
Mileage / Regen Notes
An intermittent EGR temperature sensor fault may inhibit or delay active DPF regeneration cycles, as the ECM requires valid EGR temperature data to confirm safe regen conditions. Regen inhibit or derate conditions may occur when the fault is active.
System Interactions
SPN 411 FMI 0 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 411 FMI 0 — 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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