What is SPN 521133 & How to Solve It?

What is SPN 521133

SPN 521133: Refers to a fault related to the exhaust gas temperature (EGT) sensor in the aftertreatment system.

When SPN 521133 is triggered, it indicates that the ECM is receiving incorrect data from the EGT sensor, which could affect the performance of the aftertreatment system and emissions control.

Why It Happened

This fault is typically caused by:

• A malfunctioning or damaged exhaust gas temperature sensor.
  
• Poor wiring connections or damaged cables between the sensor and ECM.
  
• Contamination or corrosion in the sensor or connectors.
  
• Abnormal temperature conditions affecting the sensor’s readings.
  
• A failure in the ECM processing the sensor’s data.
  
  

How to Resolve It

To resolve SPN 521133:

1. Inspect the wiring and connectors between the EGT sensor and ECM for damage or corrosion.
   
2. Test the EGT sensor for faults and replace it if needed.
   
3. Check the aftertreatment system for any issues that could affect the sensor’s performance.
   
4. Clear the fault code and restart the engine to verify the fix.
   
   

How to Avoid Before It Happens

To prevent SPN 521133:

• Regularly inspect the aftertreatment system and exhaust sensors.
  
• Check wiring connections and replace any damaged parts.
  
• Monitor exhaust gas temperature with real-time alerts using Clue.
• Keep equipment management simple to avoid errors.