ATC 001549.13 – Heater Valve Not Calibrated. John Deere System Advisory.

ATC 001549.13 (ATC 1549.13)

Code: 001549.13

Shortcode: 1549.13


The error code, ATC 001549.13, is triggered when the heater valve (B131) is found to have an invalid calibration or is not yet calibrated. This situation can lead to improper operation of the heater valve, affecting the heating system’s ability to accurately regulate the cabin temperature based on the control unit’s commands.


Due to the calibration issue, the heater valve may not function correctly, potentially resulting in either insufficient heating or overheating within the cabin. This can compromise the comfort and safety of the vehicle’s occupants.


  • Inspect Heater Valve and Connections: Ensure that the heater valve and its connections are intact and properly configured.
  • Calibrate Heater Valve: Use appropriate diagnostic tools and software to calibrate the heater valve. Follow the manufacturer’s guidelines to ensure the calibration is performed accurately.
  • Test Heater Valve Functionality: After calibration, test the heater valve to confirm it operates according to specifications and responds correctly to HVAC system commands.
  • Check Overall HVAC System Performance: Ensure that the entire HVAC system is functioning cohesively with the newly calibrated valve. Adjustments to other components may be necessary to optimize performance.
  • Reset Fault Codes and System Check: Clear the fault code from the system and perform a comprehensive check to ensure no other HVAC issues remain.


Regular calibration and maintenance of HVAC components are vital for optimal system performance and occupant comfort. Keeping components like the heater valve properly calibrated helps prevent mechanical and operational issues, ensuring the system remains efficient and reliable. Calibration should be part of regular vehicle maintenance, especially after repair or replacement of related parts.