BCU 002386.19 – E27 Beacon Light, Incorrect CAN Bus Message from Multiple Control Units. John Deere System Advisory.

BCU 002386.19 (BCU 2386.19)

Code: 002386.19

Shortcode: 2386.19


Error code BCU 002386.19 is triggered when the output for controlling the E27 beacon light on a John Deere vehicle is simultaneously energized by more than one control unit, indicating a conflict or misconfiguration within the vehicle’s CAN bus system. This situation can lead to erratic behavior of the beacon light, including unintended flashing or failure to operate as expected, due to conflicting signals received by the Power Module (High Frequency) PC6.


The system may respond by logging the conflict and potentially displaying a warning to the operator. Depending on the nature of the miscommunication, it might also temporarily disable the affected beacon light to prevent erratic operation and reduce the risk of damage to the electrical system.


  • Identify Contributing Control Units: Use diagnostic tools to determine which control units are sending conflicting signals to the E27 beacon light output. This will help identify the source of the problem.
  • Inspect CAN Bus Configuration: Examine the configuration and programming of the CAN bus system to ensure that it properly routes commands to the beacon light, preventing multiple control units from attempting to control the same output.
  • Resolve Configuration Errors: Correct any programming errors or misconfigurations discovered during diagnostics. This may involve reprogramming one or more of the control units to ensure only the appropriate signals are sent to control the beacon light.
  • Test Beacon Light Operation: After making adjustments, test the beacon light to ensure it responds correctly to control inputs and that no additional or conflicting commands affect its operation.
  • Reset the Power Module and Clear Diagnostic Codes: Reset the power module PC6 and any other involved control units to clear the diagnostic trouble codes and reestablish proper system operation.
  • Monitor System Post-Repair: Continue to monitor the beacon light to ensure that it functions consistently without further signal conflicts. Verify that the corrective actions have resolved the issue completely.


Proper configuration of the CAN bus system to prevent command conflicts is essential for the reliable operation of vehicle systems. Regular checks and updates of the system configurations can prevent potential operational conflicts and ensure smooth operation of all connected devices. This is especially important in complex systems where multiple control units communicate over a common network, as misconfigurations can lead to unintended equipment behaviors and safety issues.