New Holland NH 2013 – Transmission Control Unit (TCU) or Armrest Controller / Vehicle Control Module (VCM): Up and Down buttons at same time

Indicates an implausible electrical condition where the control module is receiving simultaneous input signals from both the 'Up' (upshift/raise) and 'Down' (downshift/lower) buttons. Typically caused by a stuck button, an internal short circuit within the switch, or a short in the wiring harness.

• T5
• T6
• T7
• T8
• TM115 through TM190
• TS130A
• TS135A
• 8160
• 8360
• 8560

1. 1

   Inspect the up and down buttons on the transmission shift lever, multi-function joystick, or armrest for physical jamming by dirt, debris, or a broken return spring.

2. 2

   Remove the switch or joystick, disconnect its wiring harness, and perform a switch continuity test using a multimeter. A closed circuit for both 'Up' and 'Down' pins simultaneously without pressing the buttons indicates an internal short.

3. 3

   Inspect the wiring harness running from the joystick/armrest to the TCU for chafed insulation, pinched wires, or melted lines that could bridge the up and down signal wires.

4. 4

   Check the electrical connectors at the base of the joystick and at the ECU for moisture, corrosion, or bent pins causing signal bridging.

1. 1

   Power Down

   Turn off the tractor and disconnect the negative battery cable to prevent electrical spikes.

2. 2

   Access the Switch

   Carefully pry off the trim panels on the armrest console or remove the screws securing the transmission control lever/joystick housing.

3. 3

   Disconnect

   Unplug the electrical connector leading to the faulty up/down shift buttons.

4. 4

   Replace the Component

   If the buttons are integrated into the knob, remove the retaining set-screw or clip holding the knob to the lever shaft and pull the knob off. If it is a modular rocker/push switch, pop the faulty switch out of its bezel. Install the new switch assembly or replacement control knob.

5. 5

   Repair Wiring (If Applicable)

   If the diagnostic test pointed to the harness rather than the switch, locate the shorted section of the wire. Cut out the damaged section, solder in new automotive-grade wire, and seal it with heat-shrink tubing.

6. 6

   Reassemble & Test

   Reconnect the wiring harness, reassemble the armrest/console trim, and reconnect the battery. Turn the ignition on, clear the stored fault codes from the dashboard/monitor, and test the up and down shifting functions to verify the repair.