BCU 523753.18 – Raising Deadband Too Low in M08 Stepper Motor for Hitch During Calibration. John Deere System Advisory.

BCU 523753.18 (BCU )

Code: 523753.18



Diagnostic trouble code BCU 523753.18 is activated when the raising deadband—the clearance between the adjustment cam of the stepper motor and the raise valve of the hitch valve—is found to be excessively low during calibration of the stepper motor for the hitch. This insufficient clearance can lead to mechanical interference, potentially causing rapid wear or damage to the stepper motor and hitch valve, and may affect the precision and responsiveness of the hitch control.


The BCU may restrict the operation of the hitch to prevent potential damage from the lack of sufficient clearance, and the system may trigger alerts to notify the operator of the calibration issue.


  • Inspect and Adjust Mechanical Linkages: Carefully examine the linkage between the stepper motor and the hitch valve. Check for signs of wear or improper alignment that could reduce the deadband.
  • Increase Deadband to Optimal Levels: Adjust the position of the adjustment cam or related components to increase the deadband to within the manufacturer’s recommended specifications.
  • Calibrate the Hitch System: After mechanical adjustments, recalibrate the hitch system to ensure that the new settings are effectively implemented and that the system operates smoothly.
  • Test System Operation: Operate the hitch through its full range of motion after adjustments to ensure that the hitch responds correctly to controls and that the deadband adjustment has resolved the issue.
  • Implement Preventative Maintenance: Establish a routine maintenance schedule to regularly check the hitch mechanism and adjust as necessary to avoid issues related to inappropriate mechanical clearances.


Proper calibration and maintenance of the hitch system are critical to ensuring efficient operation and longevity of the machinery. Regular adjustments and checks help prevent mechanical failures and ensure the hitch operates reliably under various conditions. Addressing issues like a too-low raising deadband promptly is crucial to maintaining the operational efficiency and safety of the equipment.