SPN 2261 FMI 0Turbocharger
Turbocharger/Supercharger Boost Control A Position Exceeded Learning Limit
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Connector Pinout — in guided session
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Overview
Fault Code
SPN 2261 / FMI 0
Category
Turbocharger
Derate Risk
No
Regen Inhibit
No
Inducement Risk
No
Component Location: The VGT actuator and position sensor are mounted on the turbocharger assembly, typically located on the intake side of the engine.
Common Symptoms
- Low boost pressure at high engine load
- Reduced engine power and acceleration
- Black smoke from exhaust under load
- Turbo actuator at maximum position without achieving target boost
- Poor throttle response
- Check engine light illuminated
Root Causes
- VGT actuator mechanical binding or seized vanes Faulty VGT position sensor Turbocharger carbon buildup restricting vane movement VGT actuator calibration drift or exceeded learning range Damaged or disconnected VGT linkage
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Derate Behavior
Power Derate
No
System Interactions
SPN 2261 FMI 0 interacts with the following systems and may trigger cascading faults if not resolved promptly.
Boost pressure — engine air/fuel ratio and power output affected
EGR system — boost pressure affects EGR flow calculations
Aftertreatment — low boost can cause incomplete combustion and DPF loading
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 2261 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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