What is SPN 3720 & How to Solve It?

What is SPN 3720:

SPN 3720 indicates a fault with the Exhaust Gas Recirculation (EGR) Valve Control Circuit. This code means the engine control module (ECM) has detected an issue with the electrical circuit controlling the EGR valve, which plays a crucial role in reducing nitrogen oxide emissions by recirculating a portion of exhaust gas back into the engine.

‍

Why This Happens

Common causes include:

• Faulty or stuck EGR valve.
  
• Damaged wiring or connectors in the EGR valve control circuit.
  
• Corrosion or loose electrical connections.
  
• Faulty ECM or software glitches affecting the circuit.
  
  

How to Fix It

To resolve this fault:

1. Inspect the EGR valve and control circuit wiring for damage or corrosion.
   
2. Test the EGR valve operation and replace if faulty.
   
3. Repair or replace damaged wiring or connectors.
   
4. Clear the fault code and verify EGR system performance.

‍

How to Avoid It Before It Happens

Prevent this fault by:

• Regularly maintaining and cleaning the EGR valve.
  
• Inspecting wiring and connectors during routine service.
  
• Performing diagnostics to detect early electrical issues.
• Use Clue’s Preventive Maintenance to regularly inspect the EGR valve, wiring, and connectors, ensuring early detection of potential issues.