BCU 523826.04 – Nonexistent Function Activated. John Deere System Advisory.

BCU 523826.04 (BCU )

Code: 523826.04



Diagnostic trouble code BCU 523826.04 is triggered when the control unit detects an open circuit at address BCU071 during an attempt to activate a function that does not exist. This situation typically arises due to configuration errors, incorrect programming, or a malfunction within the control unit that leads to erroneous function calls.


The control system may log this error and possibly alert the operator via an error message on the dashboard or control panel. The system is designed to ignore such erroneous activations without affecting the operation of existing, valid functions.


  • Verify System Configuration: Check the system’s configuration settings to ensure all programmed functions match the equipment capabilities and no invalid functions are set.
  • Inspect Control Unit and Wiring: Examine the control unit and associated wiring for address BCU071 to identify any signs of damage or misconnections that could be erroneously triggering this diagnostic code.
  • Software Diagnostics: Run diagnostics on the software to ensure there are no bugs or errors causing the system to attempt activation of non-existent functions. Look specifically for misrouted commands or incorrect address usage.
  • Update Firmware/Software: Ensure that the control unit’s firmware or software is up to date. An update may correct known issues that cause the system to recognize or attempt to activate non-existent functions.
  • Consult Technical Support: If the issue is not resolved by basic troubleshooting, consult with John Deere technical support for expert advice or possible system recalibration.


Maintaining the integrity and accuracy of the control unit’s programming is crucial for the correct operation of all machinery functions. Regular system checks and updates can prevent issues related to erroneous function activations, helping to avoid unnecessary alerts and ensuring efficient machinery operation. This proactive approach can also aid in identifying potential system improvements and preventing future errors.

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