BCU 523703.04 – B19 Right Draft Sensor, Voltage Too Low During Calibration. John Deere System Advisory.

BCU 523703.04 (BCU )

Code: 523703.04



Error code BCU 523703.04 is triggered when the Basic Control Unit (BCU) of a John Deere vehicle detects an abnormally low voltage, below 0.25 volts, at the signal input of the right draft sensor during its calibration phase. This diagnostic trouble code indicates a potential malfunction within the draft sensor circuit, such as a poor connection, a break in the wiring, or a faulty sensor, which prevents adequate voltage from being delivered to the sensor.


The low voltage detection may lead to incorrect or unreliable readings from the right draft sensor, affecting the tractor’s hitch control system. This could compromise the tractor’s ability to adjust and control the hitch accurately, potentially impacting agricultural operations and implement performance.


  • Inspect the Right Draft Sensor and Wiring: Check the sensor and its associated wiring for any signs of damage, disconnection, or wear that could cause low voltage readings. Look specifically for loose connections, corroded terminals, or broken wires.
  • Test Sensor Voltage: Use a multimeter to measure the voltage at the draft sensor’s input during calibration to verify the low voltage condition.
  • Repair or Replace Faulty Components: If any issues are found with the sensor or its wiring, undertake repairs or replace the faulty components to restore proper functionality. Ensure all connections are secure and well-insulated.
  • Re-calibrate the Draft Sensor: After making any necessary repairs or replacements, recalibrate the right draft sensor to ensure it provides accurate data to the BCU.
  • Reset the BCU: Clear any diagnostic trouble codes from the BCU and reset the system to ensure it recognizes the updates and operates with the correct settings.
  • Test the System Functionality: Conduct functional tests to confirm that the draft sensor now operates correctly and delivers reliable data during calibration.
  • Implement Regular System Maintenance: Schedule regular inspections and preventive maintenance for the draft sensor and related electrical systems to prevent future issues. Regular checks can help detect and resolve potential problems early, ensuring continued reliable operation.


Maintaining accurate sensor functionality is essential for precision agricultural operations, where control systems depend on reliable data to operate effectively. Ensuring that sensors and their connections are in good condition through regular maintenance and timely repairs is key to achieving optimal performance and prolonging the lifespan of agricultural machinery.