AIC 521401.02 – Front Hitch Control Lever Switch/Sensor Conflict. John Deere AIC System Alert.

AIC 521401.02 (AIC )

Code: 521401.02



This error code indicates a malfunction in the Front Hitch Control Lever system, where there is a conflict between the detent switch and the lever’s actual position. This issue is compounded by discrepancies in signal voltage from the SCV X control lever, which is either out of range or misaligned with the switch status and potentiometer signal voltage. Such conflicts can lead to improper functioning of the front hitch control system, affecting the precision and reliability of front hitch operations.


To prevent potential malfunctions or safety hazards related to incorrect hitch positioning, the system has restricted the functionality of the front hitch control lever, limiting its operational capabilities.


  • Inspect the front hitch control lever and associated detent switch for physical alignment and signs of wear or damage that could affect their proper functioning. Ensure that the lever moves freely without obstruction.
  • Test the signal voltages of the SCV X control lever and the potentiometer to ensure they are within the specified range and correspond accurately to lever movements.
  • Use diagnostic tools to assess the electrical continuity and functionality of the switch and potentiometer. Check for any electrical faults that could be causing the voltage discrepancies.
  • Rectify any identified issues by adjusting, repairing, or replacing the faulty components. Ensure all replaced parts are correctly calibrated and integrated into the system.
  • After making necessary repairs, recalibrate the front hitch control system and conduct a comprehensive operational test to confirm that all issues have been resolved and that the system functions correctly without any conflicts.


Maintaining the accuracy and reliability of control levers and their associated sensors is crucial for the effective operation of machinery. Regular maintenance, precise calibration, and prompt repair of detected issues are essential practices that ensure the safety and efficiency of the equipment’s operations.