BCU 523703.04 – Low Voltage Detected in Right Draft Sensor During Calibration. John Deere System Advisory.

BCU 523703.04 (BCU )

Code: 523703.04



Diagnostic trouble code BCU 523703.04 is triggered when the basic control unit (BCU) detects a voltage at the signal input of the right draft sensor that is too low, falling below 0.25 volts during calibration. This low voltage condition suggests a malfunction within the draft sensor circuit, which may be due to issues such as poor connections, broken wiring, or a faulty sensor.


In response to this fault, the BCU may deactivate the affected sensor to prevent erroneous draft measurements, which could lead to improper functioning of agricultural equipment relying on accurate sensor input for operations.


  • Inspect Wiring and Connections: Carefully examine the wiring and connectors leading to and from the right draft sensor. Check for any signs of damage, wear, or loose connections that might be causing voltage drops.
  • Test the Sensor Output: Use diagnostic tools to measure the voltage output from the draft sensor during normal operations to confirm the presence of low voltage.
  • Replace or Repair Faulty Wiring: If any wiring issues are identified, repair or replace the affected sections to ensure proper voltage levels are maintained.
  • Check the Sensor’s Functionality: If the sensor itself appears to be the source of the problem due to malfunction or degradation, consider replacing it to restore correct function.
  • Re-calibrate and Test the System: After repairs or replacements, recalibrate the sensor and test it under normal operational conditions to ensure it is providing accurate readings.


Regular checks and maintenance of sensor systems are vital to prevent malfunctions that can affect the performance and efficiency of equipment. Ensuring that all components function correctly and are within specified voltage ranges helps maintain operational reliability and prolongs the lifespan of agricultural machinery.