BCU 522451.03 – Non-Existent Function Activated, Open Circuit Detected. John Deere System Advisory.

BCU 522451.03 (BCU )

Code: 522451.03



Error code BCU 522451.03 is triggered when the Basic Control Unit (BCU) of a John Deere vehicle detects an open circuit at the time a nonexistent function is activated in address BCU071. This diagnostic trouble code indicates that there has been an attempt to activate a function that does not exist within the system’s configuration, and the corresponding circuit is open, which could be due to a misconfiguration, a programming error, or an incorrect operator input.


The system may not respond to the attempted activation as the function does not exist. The open circuit detection is likely a safety or diagnostic check to ensure all configured functions are operating correctly.


  • Check System Configuration: Verify the programming and configuration of the BCU to ensure that no incorrect or nonexistent functions are assigned or being attempted to activate. This may involve reviewing software settings or system documentation.
  • Inspect Wiring and Connections: Although the function does not exist, an open circuit suggests potential issues in the wiring. Examine the wiring harness associated with BCU071 for any signs of disconnection, damage, or misrouting that might erroneously trigger this code.
  • Diagnose Control Unit: Use diagnostic tools to further investigate the cause of the error, especially to determine why the system is attempting to activate a nonexistent function. Check for any updates or patches that might correct system errors or misconfigurations.
  • Reset the BCU and Clear Diagnostic Codes: After checking and correcting any configuration or wiring issues, reset the BCU to clear this and any other diagnostic trouble codes. This reset will also help reinitialize the system to its correct operational state.
  • Test System Functionality: Following the reset, perform a comprehensive test of the system to ensure that all functions are operating as intended and that no further errors are reported concerning nonexistent functions.
  • Provide Training or Guidance to Operators: If the error was triggered by operator input, provide additional training or guidance on the correct operation of the vehicle’s control systems to prevent future occurrences.


Errors like activating nonexistent functions can sometimes be indicative of deeper system misunderstandings or misconfigurations. Ensuring that operators are well-trained and that the vehicle’s software is up to date and correctly configured is essential for the smooth operation of all its systems. Regular system checks and maintenance are vital to prevent operational inefficiencies and to ensure safety and reliability.