BCU 523756.16 – Lowering Deadband Too High in M08 Stepper Motor for Hitch During Calibration. John Deere System Advisory.

BCU 523756.16 (BCU )

Code: 523756.16



The diagnostic trouble code BCU 523756.16 is issued when the lowering deadband—defined as the play between the adjustment cam of the stepper motor and the lower valve of the hitch valve—is found to be excessively high during calibration. This larger-than-optimal gap can lead to inefficient hitch operation, potentially causing delayed or imprecise movements in the hitch’s lowering function, which could impact the tractor’s operational effectiveness and implement control.


In response to this calibration issue, the BCU may limit the operation of the hitch system to prevent potential damage from the excessive deadband. The system is likely to alert the operator through fault indicators to address the calibration error.


  • Inspect Mechanical Components: Thoroughly check the mechanical linkages and components involved in the hitch’s lowering mechanism, particularly focusing on the stepper motor adjustment cam and lower valve.
  • Adjust Deadband to Appropriate Levels: If possible, make mechanical adjustments to reduce the deadband to within specified tolerances. This may involve repositioning the adjustment cam or tightening any loose components that contribute to excessive play.
  • Calibrate the Hitch System: After making mechanical adjustments, recalibrate the hitch system to ensure the deadband is set correctly and that the entire system functions smoothly.
  • Test Hitch Operation: Operate the hitch through its full range of motion to verify that the adjustments have effectively corrected the problem and that the hitch responds accurately to control inputs.
  • Regular Maintenance and Checks: Implement a regular maintenance schedule to monitor and adjust the hitch mechanism, ensuring that issues related to excessive deadband do not recur.


Regular calibration and maintenance of the hitch system are vital for maintaining the tractor’s efficiency and the effectiveness of attached implements. Addressing issues such as a high lowering deadband promptly helps ensure that the tractor operates optimally, enhances the lifespan of mechanical components, and maintains the precision required for agricultural operations.