SPN 440 FMI 0EVAPLow
Evaporative Emission System No Flow During Purge
Scan Tool — in guided session
DVOM Testing — in guided session
Connector Pinout — in guided session
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Overview
Fault Code
SPN 440 / FMI 0
Category
EVAP
Severity
Low
Regen Inhibit
No
Inducement Risk
No
Component Location: EVAP purge solenoid typically mounted on or near the intake manifold or firewall, connected to charcoal canister via hose routing along frame rail.
Common Symptoms
- MIL (check engine light) illuminated
- No noticeable driveability issues in most cases
- Fuel vapor odor near vehicle
- Failed emissions/OBD readiness test
- Possible hard start after extended soak periods
- OBD monitor showing EVAP system not ready
Root Causes
- Failed or stuck closed purge solenoid valve Collapsed, cracked, or kinked EVAP purge hose Faulty or clogged charcoal canister Vacuum supply loss to purge solenoid PCM/ECM not commanding purge due to enabling conditions not met
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Derate Behavior
Mileage / Regen Notes
SPN 440 FMI 0 is an EVAP system fault and does not directly inhibit or affect DPF regeneration cycles; regen behavior is not impacted.
System Interactions
SPN 440 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
Diagnostic Engine v7.0
Related Diagnostic Articles
Deep-dive diagnostic page: SPN 440 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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