What is SPN 5246 FMI 14 & How to Solve It?

What is SPN 5246 FMI 14:

SPN 5246 is a reductant system inducement warning, and FMI 14 indicates a special instruction or condition not defined in typical ranges.

This often means the system has entered derate or shutdown preparation due to unresolved aftertreatment issues.

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Why This Happens

• Incomplete or failed regenerations.
• DEF quality, temperature, or level faults not addressed.
• DEF pump or pressure sensor failure.
• Control module forcing derate based on emissions non-compliance.

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How to Fix It

1. Identify and resolve all active aftertreatment and DEF-related codes.
2. Check DEF tank level and quality.
3. Inspect DEF pump, lines, and sensors.
4. Perform forced regen if soot level is high.
5. Clear all codes and confirm engine returns to normal mode.

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How to Avoid It Before It Happens

1. Don’t ignore early warning lights tied to aftertreatment.
2. Ensure regens are completed fully and on time.
3. Use only clean, certified DEF.
4. Maintain system sensors and replace aging ones proactively.