What is SPN 3597 & How to Solve It?

What is SPN 3597:

SPN 3597 indicates a fault with the Aftertreatment 1 Diesel Exhaust Fluid (DEF) Quality Sensor Circuit. This sensor monitors the quality and concentration of the DEF to ensure it meets emission reduction standards. When this fault occurs, the sensor is either malfunctioning or sending an invalid signal, which can impact the efficiency of the emission control system.

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Why This Happens

Common causes include:

• Faulty DEF quality sensor.
  
• Wiring issues such as open circuits, shorts, or damaged connectors.
  
• Contaminated or degraded DEF fluid affecting sensor readings.
  
• Sensor calibration or communication errors.
  
  

How to Fix It

To resolve this fault:

1. Inspect the DEF quality sensor and wiring for damage or corrosion.
   
2. Test the sensor signal and replace the sensor if faulty.
   
3. Replace contaminated DEF fluid if necessary.
   
4. Repair or replace damaged wiring or connectors.
   
5. Clear the fault code and monitor system performance.
   
   

How to Avoid It Before It Happens

Prevent this fault by:

• Using high-quality DEF fluid and replacing it regularly.
  
• Regularly inspecting the DEF quality sensor and wiring.
  
• Keeping the DEF system clean and well-maintained.
• Use Clue’s Asset Tracking to monitor the DEF quality sensor in real time, detecting malfunctions early before they impact emission standards.