What is SPN 630 FMI 2 & How to Solve It?

What is SPN 630 FMI 2:

SPN 630 relates to the Engine Control Module (ECM), and FMI 2 means the data is erratic, intermittent, or incorrect.

This fault occurs when the ECM’s internal data or communication signal becomes unstable, which may cause abnormal engine behavior or temporary loss of control functions.

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Why This Happens

• ECM internal failure or software glitch.
  
• CAN network interference or module communication dropout.
  
• Loose power or ground to the ECM.
  
• Faulty ECM connectors or corroded terminals.
  

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How to Fix It

1. Inspect ECM power, ground, and communication lines.
   
2. Use diagnostics to check for additional module communication errors.
   
3. Reseat or replace the ECM connector if damaged or loose.
   
4. Update or reflash ECM software if a glitch is suspected.
   
5. Clear the code and monitor for stable operation.
   

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How to Avoid It Before It Happens

1. Keep ECM connectors sealed, tight, and clean.
   
2. Use diagnostic software to monitor module communication health.
   
3. Replace or upgrade ECMs approaching end-of-life cycles.
   
4. Avoid jump-starting equipment without voltage control.