SPN 2659 FMI 3EGRMedium
EGR Target Error - Voltage High
Scan Tool — in guided session
DVOM Testing — in guided session
Connector Pinout — in guided session
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Overview
Fault Code
SPN 2659 / FMI 3
Category
EGR
Severity
Medium
Derate Risk
Sometimes
Regen Inhibit
No
Inducement Risk
No
Component Location: EGR valve is typically mounted on the intake manifold or EGR cooler outlet on the engine, with the position sensor integrated into the valve body.
Common Symptoms
- Check engine light illuminated. EGR system not responding correctly to commanded positions. Possible elevated NOx emissions. Engine may run rough at idle or during light load conditions. EGR valve may be stuck open or closed. Scan tool shows EGR actual position not matching commanded position. Possible black smoke under acceleration if EGR stuck open. Poor fuel economy. May notice lack of power during highway driving.
Root Causes
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Derate Behavior
Power Derate
Sometimes
Mileage / Regen Notes
This fault typically does not directly inhibit active DPF regeneration. However, if the ECM cannot accurately control EGR flow due to the sensor circuit fault, exhaust gas temperatures and oxygen content may be affected, which can indirectly impact regen efficiency. Monitor for secondary faults related to DPF differential pressure or outlet temperature if regen issues occur alongside this code. Parked regen should still be available in most cases.
System Interactions
SPN 2659 FMI 3 interacts with the following systems and may trigger cascading faults if not resolved promptly.
TSB Reference: No confirmed TSBs — verify in OEM service portal. Check for manufacturer-specific bulletins related to EGR position sensor harness routing and connector sealing updates. Some OEMs have released harness repair kits for EGR sensor circuits prone to chafing near exhaust manifold.
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 2659 FMI 3 — 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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