ATC 000168.03 – Control Unit Supply Voltage Too High. John Deere System Advisory.

ATC 000168.03 (ATC 168.03)

Code: 000168.03

Shortcode: 168.03


This error code, ATC 000168.03, indicates that the control unit has detected a supply voltage exceeding the normal threshold, specifically more than 16 volts. This excessive voltage measurement was identified at pin 22, lead 0402, ELX. Such high voltage can pose a risk to the electronic components by potentially causing overheating or damage to the circuitry.


The high voltage condition may prompt the control unit to enter a protective mode to prevent damage to the electrical system. This could lead to reduced functionality or a shutdown of certain operations within the equipment to safeguard the electronic components.


  • Check Power Supply Source: Verify the source of power supply for anomalies that could cause an overvoltage condition. Inspect for faulty regulators or alternators that might be supplying excessive voltage.
  • Inspect Electrical Connections: Look for any loose, corroded, or damaged connections that could affect voltage levels. Ensuring all connections are secure can help maintain proper voltage levels.
  • Verify System Voltage with Multimeter: Use a multimeter to check the voltage at pin 22, lead 0402, ELX, and compare it with the standard specifications. This will confirm if the voltage is consistently too high.
  • Examine Related Components: Inspect associated components that might influence voltage distribution, such as the voltage regulator and battery. Replace components if they are found to be faulty.
  • System Reset and Re-test: After any repairs or adjustments, reset the control unit and re-test the system to ensure that the voltage levels are within the acceptable range and that the fault code does not reappear.


It is crucial to address voltage discrepancies promptly to avoid long-term damage to the electrical systems of the machinery. Regular monitoring and maintenance of the electrical system can prevent such issues and ensure reliable operation of your John Deere equipment.