SPN 202 FMI 0Fuel
Fuel Injector Circuit Malfunction - Cylinder 2
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Overview
Fault Code
SPN 202 / FMI 0
Category
Fuel
Derate Risk
No
Regen Inhibit
No
Inducement Risk
No
Component Location: Cylinder 2 fuel injector is mounted in the cylinder head valve cover area, second position from front of engine on inline engines or per firing order on V-configs.
Common Symptoms
- Rough idle or engine misfire
- Increased white or blue smoke from exhaust
- Reduced engine power and performance
- Increased fuel consumption
- Engine running on reduced cylinder count
- Audible change in engine operation
- Diesel fuel smell in exhaust
Root Causes
- Failed or shorted fuel injector solenoid on cylinder 2
- Damaged or chafed injector wiring harness causing short to ground or open circuit
- Corroded or loose injector connector at cylinder 2
- Failed injector driver circuit on ECM/ECU output stage
- Internal injector failure causing out-of-range current draw
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Derate Behavior
Power Derate
No
Mileage / Regen Notes
SPN 202 FMI 0 will typically inhibit active DPF regeneration due to incomplete or abnormal combustion in cylinder 2, risking unburned fuel loading and DPF damage; engine may be derated.
System Interactions
SPN 202 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 202 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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