Case IH 2460 - UCM – UCM: Shuttle lever R1 switch voltage too high

The electronic control unit is receiving a voltage signal from the shuttle lever's 'R1' (Reverse 1) switch circuit that exceeds the expected maximum threshold (typically >4.5V on a 5V reference circuit). This indicates a short to power or an open ground, causing the transmission to default to neutral or disable directional changes.

• VESTRUM CVX
• Case IH Maxxum Series (110, 115, 120, 125, 130, 140, 150)
• Case IH Puma Series (140, 150, 165, 180, 210, 260)
• Case IH Magnum Series
• Case IH Farmall Series (95U, 105U, 115U Pro EP)

1. 1

   Cycle the shuttle lever rapidly between Forward, Neutral, and Reverse multiple times to free up a potentially stuck micro-switch.

2. 2

   Inspect the multi-pin connector at the base of the steering column shuttle lever and the connectors at the UCM for bent pins, corrosion, or moisture ingress.

3. 3

   Perform a circuit voltage drop test on the R1 switch signal wire to check for a constant 12V (short to power) or an open ground.

4. 4

   Check the UCM power supply fuses (e.g., F-051 5A, or 10A/20A UCM fuses in the cab panel) to ensure clean power and ground.

1. 1

   Safely Prep the Machine

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

2. 2

   Access the Lever

   Remove the plastic steering column shrouds/cowling to expose the base of the power shuttle lever assembly.

3. 3

   Disconnect and Isolate

   Disconnect the electrical harness connecting the shuttle lever to the main cab harness.

4. 4

   Bench Test the Lever

   Using a multimeter set to Ohms/Continuity, test the pins corresponding to the R1 (Reverse) switch while moving the lever into the reverse position. If the switch shows infinite resistance when closed or is internally shorted to the reference voltage pin, the internal switch has failed, and the entire shuttle lever assembly must be replaced.

5. 5

   Harness Inspection

   If the lever tests good, the fault lies in the wiring. Trace the harness from the steering column down to the UCM. Repair any chafed wires that are shorting to a power source, and repair any broken ground splices.

6. 6

   Reassembly

   Plug the shuttle lever back into the harness, reinstall the steering column shrouds, and reconnect the battery.

7. 7

   Clear Codes and Calibrate

   Turn the key to the ON position. Use the tractor's dot-matrix display, H-Menu, or the Electronic Service Tool (EST) to clear the stored 2460 fault code.

8. 8

   Test Operation

   Start the tractor and perform a functional test by engaging forward and reverse to ensure the transmission engages smoothly and the code does not return.