What is FMI 21 & How to Solve It?

What is FMI 21:

FMI 21 refers to incorrectly calibrated sensor. The ECM detects that the sensor’s calibration is incorrect, which can result in inaccurate readings and affect system performance.

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Why This Happens:

• Faulty sensor or calibration error.
  
• Wiring issues affecting signal transmission.
  
• Sensor misalignment or mechanical interference.
  
• ECM failure to process the calibration correctly.
  
  

How to Fix It:

1. Test the sensor and verify its calibration.
   
2. Recalibrate the sensor using the manufacturer’s specifications.
   
3. Inspect wiring and connectors for proper signal transmission.
   
4. Replace the sensor if it cannot be recalibrated.
   
5. Perform a full system diagnostic to ensure proper sensor function.
   
   

How to Avoid It Before It Happens:

• Perform routine sensor calibration checks.
  
• Regularly inspect wiring and connectors.
  
• Ensure correct sensor alignment and installation.
  
• Clue’s equipment maintenance services monitor sensor calibration and help prevent errors from affecting engine performance.