What is SPN 5826 FMI 16 & How to Solve It?

What is SPN 5826 FMI 16:

SPN 5826 relates to a J1939 communication issue, typically between control modules. FMI 16 means the data from a specific source (often an emissions-related module) is missing or unavailable.

This code appears when a control module — such as the engine, aftertreatment, or transmission ECM — is not sending critical data over the network, often due to a lost signal or power issue.

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Why This Happens

• Failed control module or unexpected shutdown.
• Faulty wiring or connector on the J1939 network.
• Poor grounding or low system voltage.
• Intermittent module reboots due to overheating or signal loss.
• Loose terminating resistor causing signal reflection.

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How to Fix It

1. Use diagnostics to identify which module is missing from the network.
2. Inspect CAN wiring and connectors for damage or looseness.
3. Test battery voltage and ground continuity to affected module.
4. Replace or reflash the module if it fails to respond.
5. Check terminating resistors to ensure 60-ohm network resistance.
6. Clear the code and retest communication.

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How to Avoid It Before It Happens

1. Protect wiring and connectors from vibration and corrosion.
2. Regularly inspect CAN harnesses and ground points.
3. Avoid jump-starting with unstable voltage, which can disrupt modules.
4. Test communication reliability during PM inspections.