What is SPN 521133 FMI 13 & How to Solve It?

What is SPN 521133 FMI 13:

SPN 521133 FMI 13 indicates a fault with the Diesel Exhaust Fluid (DEF) Pump Motor Circuit – Electrical Open. This code means the engine control module (ECM) has detected an open circuit or electrical interruption in the DEF pump motor wiring or connections. The DEF pump motor is responsible for delivering Diesel Exhaust Fluid to the SCR system for emissions reduction.

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Why This Happens

Common causes include:

• Broken or disconnected wiring in the DEF pump motor circuit.
  
• Corroded or loose electrical connectors.
  
• Faulty DEF pump motor.
  
• Faulty Engine Control Module (ECM) or software issues.
  
  

How to Fix It

To resolve this fault:

1. Inspect the DEF pump motor wiring and connectors for damage or corrosion.
   
2. Repair or replace any broken or disconnected wires.
   
3. Test the DEF pump motor for proper operation and replace if faulty.
   
4. Clear the fault code and verify system performance.
   
   

How to Avoid It Before It Happens

Prevent this fault by:

• Regularly inspecting the DEF pump motor wiring and connections.
  
• Keeping connectors clean and secure.
  
• Performing routine diagnostics to detect electrical issues early.
• Utilize Clue’s Equipment Tracking to monitor the DEF pump motor’s performance and detect electrical issues early to avoid interruptions in emissions control.