FMI 18 — Value too low (moderately severe)
The reading is below normal at a middle warning level — more serious than FMI 17, less than FMI 1.
What it typically points to
A developing under-condition that often precedes a derate.
Codes with FMI 18
- SPN 94 FMI 18Fuel Delivery Pressure
- SPN 100 FMI 18Engine Oil Pressure
- SPN 102 FMI 18Intake Manifold #1 Pressure (Boost)
- SPN 111 FMI 18Coolant Level
- SPN 157 FMI 18Injector Metering Rail 1 Pressure (Fuel Rail)
- SPN 168 FMI 18Battery Potential / Power Input 1
- SPN 1761 FMI 18Aftertreatment 1 DEF Tank Volume
- SPN 3364 FMI 18Aftertreatment 1 DEF Quality
- SPN 4364 FMI 18Aftertreatment 1 SCR Conversion Efficiency