CSM 523625.02 — ATC Fan Speed Switch Mismatch

CSM 523625.02 (CSM )

Code: 523625.02



This error code, CSM 523625.02, indicates that there is a mismatch in the Automatic Temperature Control (ATC) fan speed switch settings. This may be caused by incorrect switch positions, software glitches, or faults in the switch mechanism.


The ATC function is disabled to prevent incorrect fan speed control.


Inspect Fan Speed Switch:

  • Check the positions of the ATC fan speed switch to ensure they match the required settings. Adjust if necessary.

Test Switch Functionality:

  • Test the fan speed switch to ensure it is working correctly. Replace the switch if it is found to be faulty.

Update ATC Software:

  • Ensure that the ATC software is up-to-date. Apply any available updates or patches to correct potential software-related issues.

Check Wiring and Connections:

  • Inspect the wiring and connections associated with the fan speed switch for any signs of damage, loose connections, or corrosion. Secure and clean all connections to ensure proper operation.

Reset and Test System:

  • After addressing the issue, reset the system and perform tests to ensure the fan speed switch settings are correct and the ATC function is restored.


Regular maintenance and inspection of the ATC system, including the fan speed switch and associated wiring, can help prevent mismatches and ensure reliable operation. Proper configuration and timely software updates are essential for the accurate functioning of the ATC.

Control Units: John Deere

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