AIC 520870.02 – AIC Control Unit Fault. John Deere AIC System Alert.

AIC 520870.02 (AIC )

Code: 520870.02



This code, AIC 520870.02, indicates a significant issue with the Armrest Interface Control Unit (AIC), specifically a calibration fault or failure in the calibration memory. This problem can arise from corrupt data, software malfunctions, or hardware failures that affect the unit’s ability to store and retrieve calibration settings accurately.


Due to the critical nature of accurate calibration for proper system function, the AIC has automatically disabled the affected function to prevent incorrect operations and potential damage to the system or machinery.


  • Begin by performing a thorough diagnostic check of the AIC’s software to identify any corruption or errors that might be affecting calibration data.
  • Reset the calibration settings to their default state and attempt to recalibrate the unit. Ensure that all necessary parameters are correctly configured according to manufacturer specifications.
  • Inspect the hardware components of the AIC, particularly memory storage modules, for signs of damage or failure. Replace any faulty hardware that could be impacting the unit’s calibration capabilities.
  • Update or reinstall the firmware of the AIC if software issues are suspected. Ensure that the latest firmware version is used, as it may contain fixes for known bugs affecting calibration.
  • After completing repairs and adjustments, thoroughly test the AIC to ensure it is functioning correctly and can hold calibration settings reliably.


Maintaining the integrity of the control unit’s calibration is essential for the operational accuracy of the equipment. Regular checks and maintenance of the AIC, including software updates and hardware inspections, are crucial for preventing calibration issues and ensuring long-term reliability and performance.