What is SPN 1481 & How to Solve It?

What is SPN 1481:

SPN 1481 relates to the DPF Outlet Temperature Sensor. If this code appears without an FMI, it typically refers to a general fault in the temperature sensor’s operation or signal.

This sensor helps manage regeneration cycles. If the readings are inaccurate or missing, regen may fail or run incorrectly — affecting emissions control.

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Why This Happens

• Sensor is damaged, dirty, or corroded.
• Wiring or connectors are shorted or loose.
• Excessive heat degrading the sensor response.
• Intermittent communication loss during regen.

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How to Fix It

1. Inspect the temperature sensor for soot buildup or heat damage.
2. Clean the sensor if contamination is visible.
3. Test the wiring and connector for continuity and secure fit.
4. Replace the sensor if data is slow, frozen, or erratic.
5. Clear the code and confirm proper regen behavior.

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How to Avoid It Before It Happens

1. Replace exhaust sensors during scheduled aftertreatment maintenance.
2. Inspect connectors and protect them from moisture.
3. Avoid long idling that leads to poor exhaust temperature cycling.
4. Review sensor data weekly for signs of slow response.

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