PTH 521991.17 – Controller Temperature Data Valid but Below Normal Operating Range – Least Severe Level

PTH 521991.17 (PTH )

Code: 521991.17



This fault code indicates that the PTH controller temperature is slightly low, falling below the normal operational range but not at a critical level. This can be due to minor environmental fluctuations or cooling system issues.


When this error is detected, the equipment continues to operate but logs the fault for monitoring purposes. There may be minor performance inefficiencies.


Replace Controller:

  • The primary recommendation is to replace the PTH controller to ensure normal operation.

Verify Environmental Conditions:

  • Ensure the equipment is operating within the specified temperature range.
  • Avoid exposure to extremely cold conditions and implement proper warming procedures if necessary.

Monitor System Performance:

  • After replacing the controller, monitor the system to ensure normal operation and that the fault does not reappear.

Consult Technical Support:

  • If the issue persists, contact technical support for further diagnostics and assistance.


Regular monitoring of environmental conditions and ensuring the equipment operates within specified temperature ranges can prevent such issues. Implement appropriate measures to maintain a stable operating temperature.

Control Units: John Deere

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