New Holland NH 4010 – ARU (Arm Rest Module / Armrest Control Unit): Signal of Aux-stick (AUX3) out of range high

The signal voltage coming from the potentiometer for the 3rd auxiliary remote valve (AUX3) control lever/joystick is exceeding the maximum permissible threshold. This condition is typically caused by a short to power on the signal wire, an open ground circuit, or an internal failure of the potentiometer itself.

• T6
• T7
• T8
• T9
• TM
• T6000
• TVT

1. 1

   Check the physical condition of the AUX3 joystick/paddle on the armrest to ensure it springs back to the neutral position smoothly and is not physically broken or jammed.

2. 2

   Disconnect the connector at the AUX3 lever and inspect the pins for corrosion, pushed-out terminals, or moisture.

3. 3

   Using a multimeter, check the wiring harness for a short to power (e.g., 5V or 12V) on the signal wire.

4. 4

   Verify that the ground circuit to the potentiometer is intact; an open ground will cause the signal voltage to default high.

5. 5

   Perform a potentiometer sweep test by measuring the resistance of the AUX3 potentiometer while moving the lever. Look for out-of-specification resistance, erratic jumps, or an open circuit.

6. 6

   Verify that the ARU is receiving the correct supply voltage.

1. 1

   Power Down

   Turn off the tractor and disconnect the battery to prevent electrical shorts or accidental CAN bus spikes.

2. 2

   Access the Armrest Internals

   Remove the retaining screws and carefully lift the top cover/bezel of the electronic armrest console to expose the remote valve control levers.

3. 3

   Remove the Faulty Component

   Locate the AUX3 control lever/paddle. Disconnect its electrical connector. Unbolt or unclip the paddle assembly from the armrest housing.

4. 4

   Repair or Replace

   If the diagnostic checks revealed a wiring issue, repair the harness. If the potentiometer failed, install the new AUX3 control lever/paddle assembly. (Note: On most modern New Holland armrests, the potentiometer is integrated into the paddle/joystick and is replaced as a single unit).

5. 5

   Reassembly

   Secure the new lever into the armrest, reconnect the electrical plug, and reinstall the armrest cover.

6. 6

   Reconnect Power

   Reconnect the battery.

7. 7

   Calibration

   Because a new potentiometer has been installed, you must perform a remote valve/armrest calibration using the tractor's diagnostic menu (often referred to as the "H Menu") or an electronic service tool. This allows the ARU to learn the new minimum, maximum, and neutral voltage values for the AUX3 lever.