Case IH 4173 – DU (Drive Unit) module / Armrest Controller (ATC): Rear EHR control No.2 - not calibrated (DU module only)

The system detects that the potentiometer inside the #2 Electronic Hitch/Hydraulic Remote (EHR) lever in the cab armrest has not been calibrated, or its signal has drifted out of the expected neutral range, disabling the #2 rear remote valve for safety.

• Magnum
• Maxxum
• Steiger T4B
• MAXXUM T4E
• VESTRUM CVX
• Case IH Puma
• Case IH Magnum
• Case IH Steiger / Quadtrac
• Case IH Maxxum

1. 1

   Ensure the #2 remote lever physically returns to the center/neutral position without binding or sticking.

2. 2

   Look at your A-post or AFS Pro monitor for codes 4174 (Open Circuit) or 4175 (Short Circuit). If present, this indicates a wiring issue or a completely dead potentiometer.

3. 3

   Check if the green cylinder light is on while the lever is physically centered when the tractor prompts to 'move EHR to neutral' upon startup, indicating the potentiometer is failing or out of calibration.

1. 1

   Enter calibration menu

   Turn the key to the ON position while holding the PROG (Program) key to enter the tractor's calibration menu on the A-post display or AFS Pro monitor.

2. 2

   Navigate to calibration section

   Navigate to the ARM (Armrest) or EHR section.

3. 3

   Select lever channel

   Select the calibration channel for EHR lever 2 (usually displayed as R2).

4. 4

   Calibrate lever range

   Move the #2 lever through its full range of motion: pull it fully back into the raise detent, push it fully forward into the lower/float detent, and then let it spring back to the neutral position.

5. 5

   Save calibration

   Save the calibration and turn the key to the OFF position.

6. 6

   Wait for module to save

   Wait at least 10 to 30 seconds before turning the tractor back on to allow the module to save the new parameters.

7. 7

   Test and replace if necessary

   Test the remote. If the calibration fails to save, or if the 4173 code returns shortly after putting the tractor to work, the potentiometer inside the lever has failed. The lever assembly is a sealed unit and must be replaced.