PTH 000599.03 – Cruise Control Enable Switch Voltage Above Normal, or Shorted to High Source

PTH 000599.03 (PTH 599.03)

Code: 000599.03

Shortcode: 599.03


This fault code indicates that the cruise control enable switch is experiencing voltage above the normal range or is shorted to a high power source. This typically means the cruise control switch is stuck in the ON position or there is a short circuit causing constant power to the switch.


When this error is detected, the cruise control system may remain engaged even when it should not be, potentially leading to unsafe driving conditions. The system might disable the cruise control to prevent further issues.


Inspect Cruise Control Module (S46):

  • Check the cruise control switch for proper operation.
  • Ensure the switch is not stuck in the ON position.
  • Verify all electrical connections are secure and free from corrosion.

Test Power Train Hydrostatic Control Unit (PTH):

  • Perform diagnostic tests on the control unit to identify any faults.
  • Ensure all electrical connections to the control unit are secure and corrosion-free.

Check Wiring and Connections:

  • Inspect the wiring harness connected to the cruise control switch for any signs of damage, wear, or loose connections.
  • Repair or replace any damaged wiring as necessary.

Update Control Software:

  • Ensure the control unit software is current with the latest updates and improvements.

Consult Technical Support:

  • If the issue persists, contact technical support for further diagnostics and potential component replacement.

Monitor System Performance:

  • After addressing the issue, monitor the cruise control system to ensure normal operation and that the fault does not reappear.


Regular inspection and maintenance of the cruise control switch and associated wiring can prevent this fault. Consider environmental factors such as extreme temperatures or moisture that can impact electronic component performance.

Control Units: John Deere

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