New Holland NH 2015 – Transmission Control Unit (TCU) / Multi-function Control Module (XCM) / Armrest/Cab Controller: HI / LO shift lever switches both closed

The control module is receiving a 'closed' (active) signal from both the HI and LO position switches on the transmission shift lever at the exact same time. This indicates an internal short inside the switch itself, a short circuit in the wiring harness, or a damaged connector bridging the two signal wires.

• TM115
• TM120
• TM125
• TM130
• TM135
• TM140
• TM155
• TM165
• TM175
• TM190
• T5
• T6
• T8
• MX Magnum
• Magnum 235-340

1. 1

   Perform a switch continuity test by disconnecting the electrical connector at the base of the HI/LO shift lever and probing the switch terminals while toggling the lever. Simultaneous continuity on both HI and LO output pins indicates an internally shorted switch.

2. 2

   Check the wiring harness running from the shift lever to the Transmission Controller for pinched wires under the right-hand console, chafed insulation, or melted wires shorting together.

3. 3

   Inspect the switch connector and the controller pins for moisture, dirt, or corrosion that could be bridging the HI and LO signal pins.

1. 1

   Safety First

   Park the tractor on a level surface, engage the parking brake, turn off the engine, and disconnect the negative battery cable to prevent electrical spikes.

2. 2

   Access the Switch

   Remove the trim panels on the right-hand control console or the steering column (depending on where your specific model's HI/LO shuttle/shift lever is mounted) to expose the base of the shift lever and its wiring.

3. 3

   Disconnect the Harness

   Unplug the electrical connector linking the HI/LO shift lever switch to the main cab harness.

4. 4

   Remove the Faulty Switch

   Depending on the model, the switch may be integrated into the shift lever knob or bolted to the side of the lever assembly. Remove the retaining screws or roll pins securing the switch/knob and slide it off the lever.

5. 5

   Install the New Part

   Slide the new switch or shift lever knob into place and secure it with the mounting hardware.

6. 6

   Route the Wiring

   Carefully route the new switch wiring down the lever shaft, ensuring it will not be pinched or stretched when the lever is moved through its full range of motion.

7. 7

   Reassemble

   Plug the electrical connector back in and reinstall the console trim panels.

8. 8

   Clear Codes and Test

   Reconnect the battery. Turn the ignition on, clear the inactive fault codes from the dashboard/controller, and test the tractor to ensure the HI/LO transmission shifts correctly without throwing the NH 2015 code.