BCU 523760.31 – Turn Signal/Hazard Flasher System, Fault. John Deere System Advisory.

BCU 523760.31 (BCU )

Code: 523760.31



Error code BCU 523760.31 is triggered when the Basic Control Unit (BCU) of a John Deere vehicle detects an open circuit in the turn signal/hazard flasher system upon ignition. This diagnostic trouble code suggests a discontinuity or break in the electrical pathway necessary for the operation of the turn signal and hazard flasher system, which could be due to disconnected wires, worn-out connectors, or a malfunctioning flasher unit.


This fault results in the non-operation of the turn signals and hazard lights, which are crucial for signaling intentions and maintaining visibility, particularly in operations that involve road travel or working in proximity to other equipment and personnel.


  • Inspect Wiring and Connectors: Examine the wiring and connectors associated with the turn signal and hazard flasher system for any signs of disconnection, damage, or wear that could lead to an open circuit.
  • Test for Continuity: Use a multimeter to check for continuity in the circuit. This test helps to pinpoint the location and nature of the open circuit.
  • Replace or Repair Faulty Components: If any broken wires, faulty connectors, or malfunctioning components like the flasher unit are identified, repair or replace these to restore circuit integrity.
  • Check Switches and Relay: Inspect the turn signal switch and relay for faults that might contribute to circuit disruption. Replace if found to be defective.
  • Reset the BCU: After making necessary repairs or replacements, reset the BCU to clear the diagnostic trouble code and to ensure the system recognizes the restored circuit.
  • Test System Functionality: After repairs and a system reset, test the turn signal and hazard lights to ensure they function correctly in all operating conditions.
  • Implement Regular Electrical Maintenance: Schedule routine electrical system inspections as part of regular vehicle maintenance to prevent future issues with the turn signal and hazard flasher system.


Reliable operation of safety systems like turn signals and hazard flashers is essential for operational safety in agricultural and other heavy machinery. Ensuring these systems are functioning correctly through regular maintenance and prompt attention to issues not only supports operational safety but also complies with road safety regulations where applicable. Regular maintenance checks can help detect and rectify potential electrical issues before they lead to system failure.