BCU 523704.17 – Low Voltage Detected in Left Hand Draft Sensor. John Deere System Advisory.

BCU 523704.17 (BCU )

Code: 523704.17



Diagnostic trouble code BCU 523704.17 is activated when the basic control unit (BCU) detects an abnormally low voltage, below 0.25 volts, at the signal input of the left-hand (l.h.) draft sensor. This low voltage condition typically indicates a malfunction within the draft sensor circuit, which may be due to issues such as poor connections, broken wiring, or a faulty sensor.


The BCU may disable 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: Thoroughly examine the wiring and connectors leading to and from the left-hand draft sensor. Look for any signs of damage, corrosion, or loose connections that could cause voltage drops.
  • Test 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 maintenance and routine inspection of sensor systems are vital for the reliable operation 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. Addressing issues such as low voltage promptly can help prevent further complications and ensure the equipment operates efficiently.