RLC 000444.03 – Control Software, Supply Voltage (BAT at Terminal J4) Too High

RLC 000444.03 (RLC 444.03)

Code: 000444.03

Shortcode: 444.03


This error code is triggered when the supply voltage (BAT) at terminal J4 exceeds 16 volts. Such high voltage levels can indicate an overcharging condition from the alternator or issues with the voltage regulation system.


When this error is detected, the control software may experience limited or no functionality, leading to reduced performance or failure of specific electronic control systems within the equipment.


  • Inspect Voltage Regulator:
    • Check the voltage regulator for proper operation. A faulty regulator can cause voltage levels to rise above acceptable limits. Replace if necessary.
  • Verify Alternator Output:
    • Measure the alternator’s output voltage to ensure it is within the specified range. Repair or replace the alternator if it is overcharging.
  • Examine Battery Connections:
    • Ensure all battery terminals and connections are clean, secure, and free from corrosion. Poor connections can affect voltage regulation.
  • Inspect Wiring and Connectors:
    • Inspect the wiring harness and connectors associated with terminal J4. Look for any signs of wear, damage, or corrosion. Repair or replace any compromised wiring or connectors.
  • Update Control Software:
    • Ensure that the control software is up-to-date with the latest firmware. Software updates can include fixes for voltage handling and other related issues.


High supply voltage can lead to damage of sensitive electronic components over time. Regular maintenance of the electrical system, including battery and alternator checks, is essential to prevent such issues.

Control Units: John Deere

John Deere Parts
John Deere Logo