What is SPN 2659 FMI 18 & How to Solve It?

What is SPN 2659 FMI 18:

SPN 2659 FMI 18 refers to a high voltage condition in the Fuel Temperature Sensor Circuit. FMI 18 indicates that the ECM has detected a voltage higher than expected from the fuel temperature sensor, which can affect fuel system management and lead to performance issues.

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Why This Happens:

• Faulty fuel temperature sensor.
  
• Damaged or shorted wiring in the sensor circuit.
  
• Loose or corroded connectors in the circuit.
  
• High voltage supply or power issues affecting the sensor.
  
• ECM failure to interpret the sensor signal correctly.
  
  

How to Fix It:

1. Inspect the fuel temperature sensor for damage or malfunction.
   
2. Test the sensor’s voltage and resistance to ensure it’s within specifications.
   
3. Check wiring and connectors for visible damage or corrosion.
   
4. Replace the faulty fuel temperature sensor if necessary.
   
5. Ensure proper power supply and voltage regulation to the sensor.
   
   

How to Avoid It Before It Happens:

• Regularly inspect the fuel temperature sensor and wiring.
  
• Ensure a stable and regulated power supply to the sensor.
  
• Keep connectors clean and free from corrosion.
  
• Perform routine diagnostics to monitor sensor performance.
  
• Clue’s Fuel Management services help prevent temperature sensor-related issues by proactively monitoring the system.