What is SPN 2791 FMI 18 & How to Solve It?

What is SPN 2791 FMI 18:

SPN 2791 FMI 18 indicates a high voltage issue in the Turbocharger Boost Pressure Sensor Circuit. FMI 18 means the sensor is sending a signal that is too high, potentially leading to inaccurate boost pressure readings and poor engine performance.

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Why This Happens:

• Faulty turbocharger boost pressure sensor.
  
• Damaged or shorted wiring in the sensor circuit.
  
• Loose or corroded connectors in the sensor circuit.
  
• Malfunctioning turbocharger causing high boost pressure.
  
• ECM misinterpreting the sensor’s signal.
  
  

How to Fix It:

1. Inspect the turbocharger boost pressure sensor for damage or malfunction.
   
2. Test the sensor’s voltage and resistance to ensure proper functioning.
   
3. Check wiring and connectors for visible damage or corrosion.
   
4. Replace the faulty sensor if it’s not operating within the specified range.
   
5. Inspect the turbocharger system for excessive boost pressure.
   
   

How to Avoid It Before It Happens:

• Perform regular inspections of the turbocharger boost pressure sensor and its wiring.
  
• Ensure the turbocharger system is functioning optimally.
  
• Keep connectors clean and free from corrosion or moisture.
  
• Use diagnostic tools to monitor turbo system performance regularly.
  
• Clue’s Equipment Maintenance services can monitor turbo system performance and prevent issues before they lead to engine inefficiency.