BCU 523704.15 – Excessive Voltage in Left Hand Draft Sensor Detected. John Deere System Advisory.

BCU 523704.15 (BCU )

Code: 523704.15



The diagnostic trouble code BCU 523704.15 occurs when the basic control unit (BCU) identifies that the voltage at the signal input of the left-hand (l.h.) draft sensor exceeds 4.75 volts. This high voltage condition is indicative of a malfunction within the draft sensor circuit, potentially due to electrical shorts, incorrect wiring, or internal sensor defects.


To safeguard the equipment and prevent inaccurate sensor readings from affecting machine operations, the BCU may disable the affected sensor and signal an alert to the operator. This action helps prevent potential damage to the sensor or broader system malfunctions.


  • Inspect Sensor Wiring and Circuitry: Carefully examine the wiring and connections for the left-hand draft sensor. Look for any signs of wear, damage, or improper installation that could cause excessive voltage levels.
  • Measure Voltage and Diagnose Issues: Utilize diagnostic tools to measure voltage levels in the sensor circuit to pinpoint areas where voltage may be exceeding normal limits.
  • Repair or Replace Faulty Components: If any components of the circuit are found to be faulty or if wiring issues are identified, make necessary repairs or replace components to ensure compliance with voltage specifications.
  • Re-calibrate the Sensor: After addressing any physical or electrical issues, recalibrate the draft sensor to verify that it provides accurate and stable readings.
  • Test System Functionality: Ensure that the entire system is tested following repairs to confirm that the sensor operates within normal voltage parameters and functions correctly within the machine’s operational context.


Regular maintenance and proactive monitoring of sensor systems and electrical circuits in agricultural machinery are critical. Proper maintenance helps prevent issues like voltage irregularities, ensuring that all machine functions are optimized for reliable and efficient performance. Addressing problems like high sensor voltage promptly can significantly extend the operational lifespan and efficiency of such equipment.