ACU 523960.17 – Operator Absence Detected at Low Speeds

ACU 523960.17 (ACU )

Code: 523960.17



Error code ACU 523960.17 is activated when the machinery fails to detect the operator’s presence at low speeds. This condition may arise due to issues with the operator presence sensing system or improper engagement by the operator.


In response to this safety concern, the control unit automatically defaults the machinery to neutral to prevent unintended movement and ensure the safety of the worksite.


  • Check the operator presence sensor for functionality, including its connections and alignment. Ensure the sensor is not obstructed, dirty, or damaged.
  • Test the sensor’s responsiveness by simulating presence at varying speeds to see if it accurately detects the operator.
  • Refer to the vehicle’s maintenance guide to troubleshoot specific issues with the presence sensor, or adjust the sensitivity settings if applicable.
  • Consider resetting the sensor system to its factory settings to correct any configuration errors that might be causing detection failures.
  • If issues with the operator presence sensor persist after initial checks and adjustments, it may be necessary to replace the sensor or consult with a John Deere technician for a more comprehensive diagnostic and repair.


Ensuring the proper functioning of safety sensors like the operator presence detector is crucial for preventing accidents. Regular maintenance and timely intervention when issues are detected can significantly enhance the safety and reliability of machinery operations.