BCU 523704.02 – Distorted Signal in Left Draft Sensor During Calibration. John Deere System Advisory.

BCU 523704.02 (BCU )

Code: 523704.02



Diagnostic trouble code BCU 523704.02 is triggered when the basic control unit (BCU) detects a distorted signal characterized by a voltage variation exceeding 0.5 volts at the signal input of the left draft sensor during calibration. This indicates a malfunction within the draft sensor circuit, potentially due to issues such as faulty sensor components, damaged wiring, or interference in the signal path.


The BCU may limit or adjust the functionality of systems relying on the draft sensor’s input to mitigate potential inaccuracies or malfunctions in equipment operation, particularly in agricultural machinery where precise draft measurements are critical.


  • Inspect the Sensor and Wiring: Thoroughly examine the left draft sensor and its associated wiring. Look for any signs of damage, corrosion, or loose connections that could be causing signal distortion.
  • Test Sensor Output: Use appropriate diagnostic tools to measure the output voltage of the draft sensor during operation. Compare these readings against expected values to confirm the presence of distortion.
  • Replace or Repair Faulty Components: If the sensor or any part of its circuitry is found to be defective, replace or repair these components to ensure reliable performance.
  • Re-calibrate the Sensor: After addressing any hardware issues, recalibrate the draft sensor to ensure it provides accurate measurements.
  • Verify System Integration: Ensure that the sensor is correctly integrated into the BCU system, with no other electronic interference affecting its performance.


Maintaining accurate sensor functionality is essential for the proper operation of agricultural equipment, which relies on precise measurements for optimal performance. Regular checks and calibration of sensors can help prevent issues related to signal distortion, ensuring reliability and efficiency in the field.