Case IH 2470 - UCM – UCM: Shuttle lever C3 switch voltage too high

The control module is receiving a signal voltage from the Shuttle Lever's 'C3' switch that exceeds the maximum expected operational threshold. This typically indicates a short circuit to a higher electric potential (such as a short to the 12V battery power) or an open circuit on a 5-volt reference line.

• VESTRUM CVX
• Magnum
• Puma
• Farmall
• Skid steer loaders
• Compact track loaders

1. 1

   Cycle the shuttle lever through Forward, Neutral, and Reverse to free up mechanically stuck switches inside the pod

2. 2

   Verify the 5-volt reference voltage at the UCM and the shuttle lever connector

3. 3

   Inspect the wiring harness between the shuttle lever and the UCM for a short circuit to higher electric potential (battery +) or an open circuit

4. 4

   Check for conflicting inputs at the UCM (e.g., the system reading that the lever is in both Forward and Neutral simultaneously due to a short)

1. 1

   Power Down

   Turn off the machine and disconnect battery power to prevent electrical spikes during testing.

2. 2

   Access the Shuttle Lever

   Remove the steering column covers to access the base of the shuttle lever (FNRP pod) and its electrical connector.

3. 3

   Test the Harness

   Disconnect the shuttle lever. Using a multimeter, test the harness-side pins for continuity to ground and check for voltage shorts (with the key ON, engine OFF). If 12V is present on the C3 switch signal wire where it should not be, trace the harness back to the UCM to locate and repair the short.

4. 4

   Test the Switch

   If the harness is intact, test the internal resistance/continuity of the shuttle lever switches while moving the lever through its positions. If the C3 switch is internally shorted or reads out of specification, the switch assembly has failed.

5. 5

   Replace and Calibrate

   Replace the faulty shuttle lever assembly. Reconnect the battery, clear the fault codes from the UCM, and perform any required transmission/clutch calibrations as specified by the UCM.