ATC 001079.03 – 5-Volt Power Supply Voltage Too High. John Deere System Advisory.

ATC 001079.03 (ATC 1079.03)

Code: 001079.03

Shortcode: 1079.03


The error code, ATC 001079.03, is triggered when the voltage measured at the positive lead (lead 2093) of the power supply for the 5-volt components exceeds 5 volts. These components include the defog sensor (B143), refrigerant pressure sensor (B130), heater valve (B131), and motor for adjusting the air distribution flaps (B132). A voltage higher than 5 volts typically indicates that the circuit is either shorted to a positive supply lead or there is an internal malfunction within the control unit.


The control unit may enter a protective mode to prevent damage to the 5-volt components, which can affect various functions such as defogging, refrigerant pressure monitoring, and air distribution, leading to decreased performance in climate control and sensor readings.


  • Inspect Wiring and Connectors: Examine the wiring and connectors to the 5-volt components for signs of damage, corrosion, or improper connections that might lead to a short circuit.
  • Measure and Verify Voltage Levels: Use a multimeter to measure the voltage at lead 2093 to confirm if it exceeds the specified 5 volts.
  • Check for Shorts to Power: Look for any potential shorts between the 5-volt line and other power supply lines that might be causing the high voltage reading.
  • Evaluate the Control Unit: Inspect the control unit for signs of damage or defects that might be causing internal circuit issues.
  • Replace or Repair Faulty Components: If any issues are identified, replace or repair the affected wiring, connectors, or control unit components.
  • Reset and Test the System: After making repairs, reset the system to clear the fault code and test all affected components to ensure they are operating correctly within the normal voltage range.


Proper maintenance of electrical systems and regular checks for voltage accuracy are crucial to ensuring the safe and efficient operation of vehicle systems. Addressing voltage irregularities promptly helps maintain the reliability and functionality of sensitive components, avoiding potential system failures and ensuring optimal performance.