New Holland TMF 108 – Armrest Controller: Aux 1st remote valve LEVER potentiometer is failed in the Armrest Controller

The control module is receiving an out-of-range, erratic, or missing electrical signal from the potentiometer that monitors the physical position of the #1 auxiliary remote valve control lever on the operator's armrest.

• T4 Series (T4.80 - T4.110)
• T6 Series and T6000 Series (e.g., T6.140 - T6.175, T6030 - T6090)
• T7 Series and T7000 Series (e.g., T7.170 - T7.315, T7030 - T7070)
• T8 Series (e.g., T8.275 - T8.435)
• T9 Series (e.g., T9.435 - T9.700)
• Older TG/TM Series and MXM models

1. 1

   Verify the physical movement of the Aux 1 remote lever on the armrest. Ensure it moves freely without binding, debris interference, or physical breakage, and that it returns to the neutral position properly.

2. 2

   Inspect the wiring harness and connector at the Aux 1 lever potentiometer inside the armrest console. Look for loose pins, corrosion, or chafed wires that could cause an open or short circuit.

3. 3

   Test the supply voltage to the potentiometer (typically a 5V reference from the armrest controller). Check the signal wire for smooth voltage changes as the lever is moved. Dead spots in the resistance sweep indicate a failed internal track.

4. 4

   Attempt to recalibrate the electro-hydraulic remote (EHR) levers via the tractor's display monitor (e.g., IntelliView) before tearing into the armrest to rule out a loss of calibration causing position errors.

1. 1

   Power Down

   Turn off the tractor and disconnect the battery to prevent electrical shorts while working on the CAN-bus connected armrest.

2. 2

   Access the Armrest Console

   Carefully remove the outer covers and trim panels on the armrest control unit to expose the internal electro-hydraulic remote (EHR) lever assemblies.

3. 3

   Remove the Faulty Potentiometer

   Locate the potentiometer attached to the Aux 1st remote valve lever. Disconnect its electrical harness connector. Remove the retaining screws or clips holding the potentiometer to the lever mechanism.

4. 4

   Install the New Part

   Mount the new OEM potentiometer onto the lever assembly. Ensure the mechanical linkage/tang aligns correctly with the potentiometer's slot so that lever movement accurately sweeps the sensor. Secure it with the retaining hardware.

5. 5

   Reassemble

   Plug the electrical harness back into the new potentiometer and reassemble the armrest console covers.

6. 6

   Recalibrate

   Reconnect the battery and turn the key on. You must perform an EHR (Electro-Hydraulic Remote) valve and lever calibration procedure using the tractor's display monitor or a dealer service tool. The Armrest Controller needs to learn the new minimum, maximum, and neutral voltage values of the newly installed potentiometer to clear the error state.