John Deere CAB523641 – CAB: HVAC Temperature Adjust Control Fault

This fault code indicates an issue with the temperature selection control on the cab's HVAC panel, often part of the ClimaTrak automatic temperature control system. The signal from the temperature adjust control (cc# 075) is either out of the expected voltage range or the component has not been calibrated, depending on the specific Failure Mode Identifier (FMI) logged with the code (identified FMIs include 00, 01, 03, 04, 13, 16, and 18).

• 9470 STS
• 9570 STS
• 9670 STS
• 9770 STS
• 9870 STS

1. 1

   Verify the specific Failure Mode Identifier (FMI) on the diagnostic display to determine the exact nature of the fault (e.g., FMI 13 indicates calibration is needed, while others indicate out-of-range voltages).

2. 2

   Inspect the wiring harness and connectors associated with the HVAC control panel for visible damage, loose connections, or corrosion.

3. 3

   Check for other CAB or electrical system fault codes that might indicate a broader power supply problem to the control unit.

4. 4

   Operate the temperature control dial from minimum to maximum setting and observe the system's response for erratic behavior or lack of change.

1. 1

   Calibrate temperature control

   If the fault code FMI is 13 ('not calibrated'), perform a calibration procedure for the temperature adjust control using the machine's service menu or a John Deere service tool.

2. 2

   Test potentiometer voltage

   If calibration does not resolve the issue or the FMI indicates an out-of-range error, measure the resistance and voltage across the temperature control terminals as the dial is turned. The expected voltage range is between 0.25 VDC and 4.25 VDC. Readings outside this range indicate a faulty component.

3. 3

   Replace HVAC control panel

   If the temperature adjustment control fails testing, replace the component. This potentiometer is typically integrated into the HVAC control panel assembly.