BCU 001873.03 – Hitch Position Sensor High Voltage Error. John Deere System Advisory.

BCU 001873.03 (BCU 1873.03)

Code: 001873.03

Shortcode: 1873.03


Error code BCU 001873.03 is activated when the Basic Control Unit (BCU) of a John Deere vehicle detects a voltage exceeding 4.75 volts at the input of the hitch position sensor. This high voltage reading is unusual and suggests a potential malfunction in the sensor circuit, such as an electrical short, incorrect wiring, or other electrical issues that may cause overvoltage at the sensor.


The BCU may initiate a safety response by limiting the operation of the hitch or displaying warning alerts on the dashboard to prevent damage or incorrect functioning based on unreliable sensor data.


  • Inspect Hitch Position Sensor and Wiring: Check the hitch position sensor for signs of damage or corrosion. Carefully examine the wiring and connections leading to the sensor for shorts, frays, or other damage that could contribute to high voltage readings.
  • Measure Voltage Output: Use a multimeter to measure the voltage levels at the sensor input. Verify whether these levels consistently exceed the normal threshold.
  • Correct Wiring Issues: Repair or replace any damaged wiring or connectors that may be causing the high voltage condition. Ensure all connections are secure and properly insulated.
  • Replace Faulty Sensor: If the sensor itself is found to be defective and is contributing to the high voltage issue, replace it with a new one to ensure accurate and reliable functionality.
  • Test System Functionality: After making the necessary repairs or replacements, test the hitch system to ensure the voltage has normalized and the hitch operates correctly under all conditions.
  • Reset the BCU and Clear Diagnostic Codes: Clear any stored fault codes in the BCU and reset the system to confirm that the issue has been fully resolved and no further high voltage alerts are triggered.


Proper function and accurate readings from the hitch position sensor are crucial for the precision operation of a tractor’s hitch system. Regular maintenance and careful monitoring of the electrical system and sensor health can prevent issues like overvoltage, ensuring efficient and safe operation of your John Deere equipment. Addressing electrical issues promptly helps maintain the equipment’s functionality and extends its operational life.