SPN 190 has a few scenarios like:
SPN 190 FMI 0 – Engine Speed Data Valid But Above Normal Operational Range – Most Severe Level
SPN 190 FMI 2 – Engine Speed Data Erratic, Intermittent Or Incorrect
SPN 190 FMI 16 – Engine Speed Data Erratic, Intermittent Or Incorrect
Fix
Inspect turbo for leaks, drain oil and remove pan and inspect engine block for damage. Test the sensor.