SPN 247 FMI 2TurbochargerHigh
Turbo Wastegate Drive — Data Erratic, Intermittent or Incorrect
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Overview
Fault Code
SPN 247 / FMI 2
Category
Turbocharger
Fault Type
actuator
FMI Category
data erratic
Severity
High
Derate Risk
Yes
Regen Inhibit
No
Inducement Risk
No
Component Location: Wastegate actuator mounted on turbocharger — typically passenger side of engine. Linkage connects actuator arm to wastegate valve on turbine housing.
Common Symptoms
- Boost pressure erratic or inconsistent
- Over-boost or under-boost condition
- Engine derate under load
- Wastegate position feedback erratic in live data
- Possible black smoke under load
Root Causes
- Wastegate actuator position sensor failure
- Wastegate actuator motor failure
- Wastegate linkage binding or disconnected
- Wastegate actuator wiring — intermittent open or short
- Carbon buildup on wastegate valve preventing movement
- Boost pressure sensor fault causing erratic wastegate command
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Derate Behavior
Power Derate
Yes
Mileage / Regen Notes
High frequency 300k–600k miles. Carbon seizure increases with high idle time and short-trip operation.
System Interactions
SPN 247 FMI 2 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
TSB Reference: Cummins TSB 4021834 — Wastegate Actuator Inspection and Replacement
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.
OEM Notes
Cummins
ISX/X15: Wastegate actuator is separate from VGT system. Confirm engine has wastegate vs VGT before diagnosis.
Detroit
DD15: Uses VGT, not wastegate. SPN 247 on DD platform refers to different system — consult DDDL.
PACCAR
MX-13: Wastegate actuator known for carbon seizure at 300k+ miles. Penetrating oil and cycling often frees stuck valve.
Related Faults in This Category
OEM System Resources
ASE Training Resources
Diagnostic Engine v7.0
Related Diagnostic Articles
Deep-dive diagnostic page: SPN 247 FMI 2 — 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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