BCU 303057.03 – B27 Rate of Drop Potentiometer, Signal Voltage Too High. John Deere System Advisory.

BCU 303057.03 (BCU )

Code: 303057.03



Error code BCU 303057.03 is triggered when the Basic Control Unit (BCU) of a John Deere vehicle detects a signal voltage exceeding 4.75 V at the signal input of the B27 rate of drop potentiometer during the calibration of the hitch control. This excessive voltage reading indicates a possible malfunction within the potentiometer or its associated circuitry, which could affect the accuracy and performance of the hitch’s rate of drop settings.


The system may respond to this abnormal voltage by halting or altering the calibration process to prevent incorrect settings of the hitch’s rate of drop, potentially affecting the tractor’s operational functionality and safety.


  • Inspect the Rate of Drop Potentiometer: Check the potentiometer for any physical damage or signs of malfunction. Ensure that it is correctly installed and that its connections are secure.
  • Examine Wiring and Electrical Connections: Investigate the wiring leading to the potentiometer for signs of wear, damage, or improper connections that could contribute to high voltage readings.
  • Measure and Confirm Voltage Levels: Utilize a multimeter to measure the voltage at the potentiometer’s signal input, confirming that it indeed exceeds the normal operating range.
  • Replace or Repair Faulty Components: If the potentiometer or any related wiring is found to be defective, replace or repair these components to ensure correct functionality and signal integrity.
  • Recalibrate the Hitch Control System: Following any component replacement or repair, recalibrate the hitch control system according to the manufacturer’s specifications to ensure accurate operation.
  • Reset the BCU and Clear Diagnostic Codes: Resetting the BCU will clear the diagnostic trouble codes and help reinitialize the system settings after the repair, confirming that the issue has been effectively resolved.
  • Monitor System Operation Post-Repair: Keep a close watch on the hitch control system, particularly the rate of drop function, to ensure that the potentiometer operates within the correct voltage range and performs as expected without recurrence of the issue.


Regular maintenance checks and immediate attention to diagnostic alerts are vital for maintaining the operational efficiency and safety of agricultural equipment. Ensuring that the rate of drop potentiometer and other critical control components function correctly is crucial for precision farming operations and the prevention of mechanical failures.