What is SPN 524287 FMI 31 & How to Solve It?

What is SPN 524287 FMI 31:

This SPN code is often used as a generic placeholder on diagnostic tools when a fault exists but the system can’t map it to a known SPN.

FMI 31 means the issue is abnormal but not defined. This typically appears when OEM-specific or proprietary codes are being reported on a standard scanner.

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Why This Happens

• Fault exists but SPN isn’t recognized by your scan tool.
• Custom module sending non-standard codes.
• Software issue in control module reporting undefined SPN.
• ECM unable to label the data properly due to firmware mismatch.

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How to Fix It

1. Use OEM diagnostic software to retrieve the actual fault.
2. Scan for any other accompanying codes that may give a hint.
3. Update ECM software if it’s a known mapping bug.
4. Contact the equipment or engine manufacturer if fault persists without explanation.
5. Clear the code and observe behavior on restart.

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How to Avoid It Before It Happens

1. Use OEM diagnostic tools for deep-level fault analysis.
2. Keep ECM and telematics firmware fully updated.
3. Document unknown codes and cross-check with OEM support.
4. Replace modules sending unreadable data if repeated.