What is SPN 3222 FMI 5 & How to Solve It?

What is SPN 3222 FMI 5:

SPN 3222 FMI 5 indicates a fault in the Diesel Exhaust Fluid (DEF) Injector Control Circuit where the current is lower than normal or the circuit is open. This disrupts the proper operation of the DEF injector, impacting emissions reduction and engine performance.

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Why This Happens

• Faulty DEF injector.
• Damaged, broken, or corroded wiring or connectors in the injector circuit.
• Open circuit in the wiring harness.
• DEF injector solenoid malfunction.
• Engine control module malfunction.
  
  

How to Fix It

1. Inspect the DEF injector wiring and connectors for damage or corrosion.
2. Test the DEF injector solenoid for correct resistance and operation.
3. Repair or replace any damaged wiring or connectors.
4. Replace the DEF injector if faulty.
5. Check the engine control module for faults or updates.
6. Clear the code and verify the repair.

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How to Avoid It Before It Happens

• Regularly inspect and maintain the DEF injector and wiring.
• Use clean, high-quality DEF fluid to prevent contamination.
• Protect wiring from moisture and physical damage.
• Schedule routine diagnostic checks for early fault detection.
• Ensure efficient construction equipment management to prevent unexpected disruptions.