SPN 1349 FMI 7FuelCritical
High Pressure Fuel Pump — Mechanical System Not Responding
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Overview
Fault Code
SPN 1349 / FMI 7
Category
Fuel
Fault Type
actuator
FMI Category
actuator
Severity
Critical
Derate Risk
Yes
Regen Inhibit
No
Inducement Risk
No
Component Location: High pressure fuel pump — on engine, driven by camshaft or gear train
Common Symptoms
- High pressure fuel pump fault
- Fuel rail pressure low
- Engine derate
- Hard start or no start
Root Causes
- High pressure fuel pump worn
- Fuel supply restriction
- Fuel contamination
- Pump drive failure
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Derate Behavior
Power Derate
Yes
Mileage / Regen Notes
High-pressure pump wear common at 400k–600k miles.
System Interactions
SPN 1349 FMI 7 interacts with the following systems and may trigger cascading faults if not resolved promptly.
TSB Reference: Cummins TSB 4021673 — High Pressure Fuel Pump Diagnosis
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
X15: High-pressure pump P/N varies by model year.
Detroit
DD15: Check fuel supply pressure before condemning pump.
PACCAR
MX-13: Check fuel filter before pump replacement.
Related Faults in This Category
OEM System Resources
ASE Training Resources
Diagnostic Engine v7.0
Related Diagnostic Articles
Deep-dive diagnostic page: SPN 1349 FMI 7 — 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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