Case IH 9021 – ARM (Armrest Controller): Hitch position command potentiometer calibration results not acceptable.

This indicates that when the system attempted to calibrate the hitch position command dial/lever, the voltage values returned by the potentiometer were outside the expected parameters, erratic, or missing entirely. The system cannot accurately determine the operator's requested 3-point hitch height.

• MX Magnum
• STX Steiger
• TG Series
• Magnum (e.g., 215, 245, 275, 305, 335)
• Steiger
• STX Series
• Puma
• Maxxum
• CX/MX Series

1. 1

   Verify that the command lever or dial is securely attached to the potentiometer shaft. A loose lever slipping on the shaft is a primary cause of unacceptable calibration sweeps.

2. 2

   Check for related 5V reference codes (such as ARM 10091: Armrest Controller failure - 5 V regulator failure), which would cause the potentiometer to return bad data.

3. 3

   Inspect the wiring harness connecting the potentiometer to the Armrest Controller for chafing, pinched wires, or corroded connector pins.

4. 4

   Use a multimeter to measure the resistance sweep of the potentiometer while turning it. Look for dead spots or erratic resistance jumps that indicate internal failure.

1. 1

   Access the Sensor

   Disassemble the necessary trim panels on the tractor's armrest console to access the hitch position command potentiometer.

2. 2

   Secure the Shaft

   If the diagnostic checks revealed that the lever is loose on the potentiometer shaft, tighten the retaining hardware. If this was the only issue, proceed directly to step 5.

3. 3

   Replace the Potentiometer

   If the sensor failed the sweep test, disconnect the 3-pin wiring harness plug. Remove the retaining nut or mounting screws holding the potentiometer to the armrest bracket and remove the faulty unit.

4. 4

   Install the New Part

   Install the replacement potentiometer, secure the mounting hardware, and reattach the command lever/dial. Reconnect the wiring harness.

5. 5

   Recalibrate

   You must clear the error memory and run the Armrest Controller (ARM) calibration procedure for the hitch position command so the ECU can learn the new minimum and maximum voltage limits of the sensor.

6. 6

   Reassemble

   Once calibration is successful and the code clears, reinstall the armrest console trim.