ACU 523958.31 – Reversing Ratio Setting Fault

ACU 523958.31 (ACU )

Code: 523958.31



This error code, ACU 523958.31, indicates that the ratio between the forward and reverse set speeds is incorrect. This discrepancy in speed settings can lead to inefficient or unsafe transmission operations, especially when changing directions.


As a protective measure against potential mechanical stress or operational hazards, the control unit has limited certain functions of the machinery to stabilize performance.


  • Verify the set speed ratios for forward and reverse operations. Ensure these ratios are within the specifications recommended by John Deere to ensure balanced and efficient transmission performance.
  • Adjust the speed settings manually or through the system’s configuration interface to correct any imbalances. Consult the operator’s manual for guidance on the appropriate settings.
  • Perform a system recalibration if necessary. This may involve resetting the transmission settings to factory defaults before reconfiguring them according to operational requirements.
  • Use diagnostic tools to check for any related transmission error codes that might indicate a broader issue affecting the speed settings.
  • If difficulties with adjusting or maintaining the correct reversing ratio persist, it may be advisable to contact a John Deere service technician for further diagnostics and potential repairs.


Regular monitoring and maintenance of transmission settings are crucial, especially for equipment frequently transitioning between forward and reverse operations. Proper settings ensure not only efficient performance but also reduce wear and tear on the transmission system.