Case IH 4009 – DV Module or ARU: Signal of Aux-stick (AUX3) - out of range low (DV module only)

Signal voltage from the auxiliary control joystick or potentiometer for the 3rd remote valve (AUX3) has fallen below the minimum acceptable threshold, indicating an open circuit, a short to ground in the signal wire, a loss of reference voltage, or an internal failure of the AUX3 potentiometer itself.

• Maxxum
• Puma
• Magnum
• Steiger
• MXM Series
• MX/TG Series
• T-Series
• T8
• T6000
• TM Series
• CR Series combines

1. 1

   Inspect the wiring harness and connectors between the AUX3 joystick in the armrest and the DV module/ARU for pinched wires, chafing, or loose/corroded connector pins

2. 2

   Verify that the AUX3 potentiometer is receiving the correct reference voltage (usually 5V) and has a solid ground

3. 3

   Test the signal wire from the AUX3 stick to the module for continuity and ensure it is not shorted to ground

4. 4

   Back-probe the signal wire and monitor the voltage while moving the AUX3 stick to ensure it sweeps smoothly (if voltage drops out or stays near 0V, the potentiometer is internally faulty)

5. 5

   Verify that the ARU/DV module supply voltage is not dropping below 8V, which can trigger erratic armrest communication codes

1. 1

   Disconnect Power

   Turn off the ignition and disconnect the negative battery cable to prevent electrical shorts.

2. 2

   Access the Armrest Controls

   Carefully remove the trim and retaining screws on the tractor's armrest console to expose the auxiliary joystick assemblies.

3. 3

   Inspect and Clean

   Disconnect the electrical connector specifically for the AUX3 control stick. Clean the contacts with electrical contact cleaner and check for pushed-back pins.

4. 4

   Replace the Component

   If diagnostic tests confirmed a failed potentiometer and the wiring is intact, remove the mounting hardware for the faulty AUX3 joystick/potentiometer assembly and install the new replacement unit.

5. 5

   Reassemble

   Reconnect the electrical harness and reassemble the armrest console.

6. 6

   Recalibrate

   Reconnect the battery. Turn the key on and clear the stored fault codes. Enter the tractor's 'H' diagnostic/calibration menu (e.g., Section 4010 / 4012) to calibrate the new auxiliary joystick limits so the DV module learns the new potentiometer's center, minimum, and maximum voltage values.