Vehicles

SPN 5246 FMI 0 Engine Fault Code [Explained]

SPN 5246 FMI 0 Engine Fault Code is displayed because something is wrong. The vehicle speed is limited to 5 mph to prevent engine damage.

Causes:

  • DEF closer valve failed
  • Out of DEF fluid
  • NOx sensor failed
  • EGR not working
  • DEF failed
  • DEF pump failed
  • DEF valve failed
  • ECM issues

 

FMI 0 – Data Valid But Above Normal Operational Range (Most Severe Level)
This FMI indicates that the soot level in the DPF is extremely high and immediate attention is required. The vehicle may be in derate mode to protect the engine and aftertreatment system. Perform a forced regeneration and diagnose the cause of the excessive soot level.

FMI 1 – Data Valid But Below Normal Operational Range (Least Severe Level)
This FMI suggests that the soot level is below the threshold for triggering a regeneration, but still requires attention. Perform a manual or forced regeneration to clear the soot from the DPF and diagnose any potential issues contributing to the increased soot levels.

FMI 15 – Data Valid But Above Normal Operational Range (Moderate Level)
This FMI indicates that the soot level in the DPF is high and regeneration is needed. Perform a manual or forced regeneration and diagnose any potential issues that may be contributing to the increased soot levels.

FMI 31 – Not available or condition exists
This FMI code may indicate an issue with the communication between the engine control module (ECM) and the aftertreatment control module (ACM) or a problem with the ACM itself. Check for any issues with the wiring harness, connections, or ECM and ACM software.

Troubleshoot

  • Inspect the DPF: Visually check the DPF for damage, cracks, or leaks. Replace it if necessary.
  • Check the Diesel Exhaust Fluid (DEF) system: Verify that the DEF tank is filled and that the quality of the DEF is up to standards. Check for any leaks or blockages in the DEF lines, injector, or dosing unit.
  • Perform a forced regeneration: Using a diagnostic tool, initiate a forced regeneration to clear the soot from the DPF. Monitor the regeneration process to ensure it completes successfully. If the regeneration fails, further diagnosis may be necessary.
  • Inspect exhaust sensors: Check the exhaust gas temperature sensors, NOx sensors, and differential pressure sensor for proper operation. Replace any faulty sensors as needed.
  • Inspect the engine: Check for any issues with the engine that could contribute to excessive soot production, such as poor fuel quality, faulty injectors, or turbocharger issues.
  • Check the DPF pressure differential sensor: Inspect the sensor and its hoses for any blockages, leaks, or damage. Replace if necessary.

 

 

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