BCU 523839.14 – Information for Operator: Handbrake is On and a Gear is Selected. John Deere Advisory.

BCU 523839.14 (BCU )

Code: 523839.14



Diagnostic trouble code BCU 523839.14 is generated as an informational alert when the Basic Control Unit (BCU) detects that a gear has been selected while the handbrake is engaged. This situation is noted as potentially hazardous or indicative of an operational oversight. Importantly, this code is not stored in the control unit’s error memory, as it serves purely as a real-time warning to the operator to prevent potential mechanical stress or unsafe conditions.


The system is designed to alert the operator immediately without taking automatic corrective action. The intention is to ensure the operator is aware of the condition so they can manually correct the issue by either disengaging the handbrake or selecting a neutral gear before proceeding.


  • Acknowledge the Alert: Operators should immediately check the handbrake and gear status upon receiving this alert.
  • Correct the Condition: If the handbrake is engaged, disengage it before moving the vehicle or ensure that the vehicle is in neutral if the handbrake needs to remain engaged.
  • Routine Checks: Regularly inspect the handbrake and transmission linkage for proper function to ensure that both systems are operating smoothly and correctly.
  • Operator Training: Ensure that all operators are familiar with the importance of checking the handbrake status before engaging a gear to prevent this alert and reduce the risk of mechanical damage or unsafe conditions.


Regular training and reminders about operational procedures can greatly reduce the occurrence of such issues. Operators should always perform a routine check of the handbrake and gear status as part of their standard operating procedure before starting and moving the equipment. This practice helps maintain safety standards and prolongs the longevity of the machinery.

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