Case IH 4170 – DU (Display Unit) Module / Armrest Controller (ARM): Rear EHR control No.1 – not calibrated (DU module only)

The control lever (specifically the internal potentiometer) for the #1 rear remote valve has lost its calibration values, or the signal it is sending to the computer does not match the expected neutral position.

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

1. 1

   Verify if the green cylinder light on the A-post is illuminated when the lever is physically in the neutral (middle) position.

2. 2

   Pull the switch back slightly to test potentiometer response. If the light goes out, the tractor thinks the switch is in the 'lower' position when it is actually in neutral, confirming a calibration or potentiometer drift issue.

3. 3

   Check for related active codes 4171 (Open Circuit) or 4172 (Short Circuit) for EHR No.1, as those indicate a hard wiring failure rather than a calibration issue.

4. 4

   Attempt to recalibrate the lever before replacing any parts.

1. 1

   Enter calibration mode

   Hold the 'prog' (program) key in while turning the ignition key to the ON position.

2. 2

   Navigate to calibration menu

   Navigate the menu to find the 'ARM' (Armrest) section or the 'HH' (Hydraulic) menus. (On some displays, the lower central screen will display 'ch _' and you use the 'h' and 'm' keys to select the channel).

3. 3

   Calibrate lever

   Once in the calibration screen for Lever 1, pull the EHR lever fully back (raise detent), then push it fully forward (lower detent), and finally let it return to the neutral position.

4. 4

   Store calibration

   Turn the ignition key OFF to store the calibration values.

5. 5

   Test remote

   Wait 30 seconds before starting the tractor to test the remote.

6. 6

   Replace lever assembly

   If the lever fails to calibrate, or if the neutral light comes back on shortly after calibration, the potentiometer inside the armrest lever is failing and the lever assembly must be replaced.