What is MID 91 & How to Solve It?

What is MID 91:

MID 91 refers to an issue with the fuel injector control circuit. The ECM detects an abnormal signal from the fuel injector control circuit, which can result in improper fuel injection timing and engine misfires.

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Why This Happens:

• Faulty Fuel Injector Control Module (FICM).
  
• Shorted or damaged wiring in the injector control circuit.
  
• Loose or corroded connectors.
  
• Power supply issues affecting the FICM.
  
• ECM misinterpreting the injector control signals.
  
  

How to Fix It:

1. Inspect the Fuel Injector Control Module (FICM) and wiring for visible damage or malfunction.
   
2. Test the FICM for proper functionality.
   
3. Check connectors for tightness and cleanliness.
   
4. Replace the faulty FICM if necessary.
   
5. Ensure stable power supply to the FICM and ECM communication.
   
   

How to Avoid It Before It Happens:

• Regularly inspect the FICM and wiring for damage.
  
• Keep connectors clean and free from corrosion.
  
• Perform routine diagnostic checks to monitor injector control performance.
  
• Ensure stable power supply to the FICM and ECM.
  
• Clue’s fuel management services track injector control systems and prevent issues before they affect engine operation.