BCU 002005.09 – Incorrect CAN Bus Message from UIC. John Deere System Advisory.

BCU 002005.09 (BCU 2005.09)

Code: 002005.09

Shortcode: 2005.09


Error code BCU 002005.09 is activated when the Basic Control Unit (BCU) of a John Deere vehicle detects issues in data transfer from the User Interface Controller (UIC). This diagnostic trouble code indicates that one or more CAN bus messages transmitted by the UIC are either not being received or are only intermittently received by the BCU. This could be due to loose wiring, a faulty connection, or other disruptions within the CAN bus network that prevent reliable communication.


The BCU may signal a fault via the operator display or other warning systems, potentially affecting the functionality of user interface-dependent systems or reducing the operational efficiency of the vehicle due to a lack of reliable data communication.


  • Inspect CAN Bus Wiring and Connections: Thoroughly examine the wiring and connections between the BCU and UIC. Look for signs of loose connections, frayed wires, or corrosion that might be causing intermittent or faulty communication.
  • Test CAN Bus Communication: Use diagnostic equipment to check the integrity of the communication between the BCU and UIC. Monitor the data flow to identify any specific points where errors or losses occur.
  • Repair or Replace Faulty Components: Address any identified issues with the wiring or connectors by repairing or replacing them as necessary to ensure a stable and secure connection.
  • Check UIC Functionality: Verify that the UIC is functioning correctly and not contributing to the problem by sending corrupt or incomplete data. If the UIC is found to be faulty, consider reprogramming or replacing it.
  • Reset the BCU and Clear Diagnostic Codes: After resolving the hardware or connection issues, reset the BCU to clear any stored error codes and re-establish baseline settings for system operation.
  • Monitor System Operation: Continue to monitor the system post-repair to ensure that communication has been fully restored and that the UIC and BCU are interacting correctly without data loss or error recurrence.


Maintaining reliable communication between the BCU and UIC is critical for ensuring the correct operation of the vehicle’s user interface and related systems. Regular checks and prompt attention to any communication issues can help prevent operational disruptions and ensure that all systems function smoothly and efficiently. This proactive maintenance is essential for preserving the integrity and performance of John Deere machinery.