FMI 15 — Data valid but above normal operating range — least severe level
The reading is real and slightly high. An early warning, not a shutdown.
Common causes
- System drifting high — early restriction, early wear or a lazy regulator
- Duty cycle or ambient conditions pushing the value up
- Sensor reading slightly high
What to test, in order
- Trend the parameter over a road test rather than one snapshot
- Compare with a companion sensor
- Inspect the system for early restriction or a weak regulator
- Recheck after service — if it climbs to FMI 16 or 0 the condition is real
Codes we document with FMI 15
SPN 3719 FMI 15DPF soot load high - least severe · VolvoSPN 3719 FMI 15DPF soot load high - least severe · CATSPN 3719 FMI 15DPF soot load high - least severe · DetroitSPN 3719 FMI 15DPF soot load high - least severe · InternationalSPN 3719 FMI 15DPF soot load high - least severe · PACCARSPN 3719 FMI 15DPF soot load high - least severe · MERCEDESSPN 3719 FMI 15DPF soot load high - least severe · MackSPN 3719 FMI 15DPF soot load high - least severe · CumminsSPN 5246 FMI 15SCR inducement level 1 · International
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