FMI 1 — Data valid but below normal operating range — most severe level
The reading is real and it is dangerously low. Low oil pressure, low coolant level and low rail pressure land here. Treat it as a real condition until proven otherwise.
Common causes
- Actual low pressure, level or flow
- Pump, regulator or supply failure
- Large leak on the circuit being measured
- Sensor drifted low
What to test, in order
- Confirm with a mechanical gauge or a second sensor before condemning anything
- Inspect for leaks, low level or a collapsed supply line
- Test pump/regulator output against spec
- Compare the sensor value at key-on with ambient/known baseline
Codes we document with FMI 1
SPN 46 FMI 1Air system pressure critically low · All makesSPN 94 FMI 1Fuel rail pressure too low · PACCARSPN 94 FMI 1Fuel pressure low · CATSPN 94 FMI 1Fuel delivery pressure below normal · DetroitSPN 94 FMI 1Fuel delivery pressure below normal · InternationalSPN 94 FMI 1Fuel delivery pressure below normal · MERCEDESSPN 94 FMI 1Fuel delivery pressure below normal · VolvoSPN 94 FMI 1Fuel delivery pressure below normal · MackSPN 94 FMI 1Fuel delivery pressure below normal · CumminsSPN 98 FMI 1Engine oil level low · All makesSPN 100 FMI 1Engine oil pressure critically low · PACCARSPN 100 FMI 1Low engine oil pressure · CATSPN 100 FMI 1Engine oil pressure low · VolvoSPN 100 FMI 1Engine oil pressure below normal - most severe · DetroitSPN 100 FMI 1Engine oil pressure below normal - most severe · InternationalSPN 100 FMI 1Engine oil pressure below normal - most severe · MERCEDESSPN 100 FMI 1Engine oil pressure below normal - most severe · MackSPN 100 FMI 1Engine oil pressure below normal - most severe · CumminsSPN 111 FMI 1Coolant level low · InternationalSPN 111 FMI 1Engine coolant level below normal - most severe · CATSPN 111 FMI 1Engine coolant level below normal - most severe · DetroitSPN 111 FMI 1Engine coolant level below normal - most severe · PACCARSPN 111 FMI 1Engine coolant level below normal - most severe · MERCEDESSPN 111 FMI 1Engine coolant level below normal - most severe · Volvo
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