What is SPN 102 FMI 18 CUMMINS & How to Solve It?

What is SPN 102 FMI 18:

SPN 102 FMI 18 in Cummins engines indicates a high voltage condition in the Intake Air Temperature Sensor Circuit. FMI 18 indicates that the signal from the sensor is too high, which can cause incorrect air/fuel mixture adjustments and lead to engine performance problems.

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Why This Happens:

• Faulty intake air temperature sensor.
  
• Damaged or shorted wiring in the sensor circuit.
  
• Corroded or loose sensor connectors.
  
• Interference from other electrical components.
  
• ECM misinterpretation of the sensor signal.
  
  

How to Fix It:

1. Inspect the intake air temperature sensor for damage or malfunction.
   
2. Test the sensor’s voltage and resistance to ensure they match specifications.
   
3. Check wiring and connectors for any signs of damage, corrosion, or loose connections.
   
4. Replace the faulty sensor if necessary.
   
5. Inspect the intake system for contamination or blockages that could affect sensor readings.
   
   

How to Avoid It Before It Happens:

• Regularly inspect the intake air temperature sensor and wiring.
  
• Keep connectors clean and free from moisture or corrosion.
  
• Ensure the air intake system is functioning properly and clear of debris.
  
• Perform routine diagnostic checks on the sensor.
  
• Clue’s Equipment Maintenance services monitor sensor health and help prevent issues before they affect engine performance.