SPN 16 FMI 0TimingHigh
Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor A)
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Connector Pinout — in guided session
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Overview
Fault Code
SPN 16 / FMI 0
Category
Timing
Severity
High
Regen Inhibit
No
Inducement Risk
No
Component Location: Crankshaft position sensor is typically at the front or rear of the engine block near the crankshaft; camshaft sensor is near the front valve cover or timing cover.
Common Symptoms
- Hard start or no start condition
- Rough idle or engine misfire
- Reduced engine power or derate
- Check engine light illuminated
- Erratic engine RPM behavior
- Failed or incomplete DPF regeneration cycle
Root Causes
- Worn or stretched timing chain/belt causing phase offset between crank and cam
- Faulty crankshaft position sensor signal or damaged tone wheel
- Faulty camshaft position sensor or reluctor wheel damage
- Timing chain tensioner failure allowing excessive slack
- Wiring harness damage, chafing, or connector corrosion on CKP or CMP sensor circuits
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Derate Behavior
Mileage / Regen Notes
SPN 16 FMI 0 will typically inhibit active DPF regeneration due to unreliable engine timing data; ECM cannot safely manage fuel injection timing required for regen.
System Interactions
SPN 16 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 16 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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