Case IH U95 – Transmission Control Module (TCU) / Transmission Controller: Synchro potentiometer signal is out of range for F2 position

The transmission controller is receiving a voltage or signal from the F2/R1 synchronizer potentiometer that falls outside the calibrated or expected limits when the transmission attempts to engage or monitor the F2 gear position.

• Puma Series (125, 140, 165, 180, 195, 210, 225)
• Maxxum Series (MXM 120, 130, 140, 155, 175, 190)
• Magnum Series

1. 1

   Inspect the wiring harness running from the transmission controller to the F2/R1 synchronizer potentiometer and solenoids for open circuits, swapped connectors, or shorts to ground.

2. 2

   Connect the diagnostic tool or enter the tractor's H-Menu to view live data. Check the displayed potentiometer reading during calibration (should read between 490 and 2000 for the F2 position).

3. 3

   Ensure the synchronizer is not mechanically jammed in the driveline, which would prevent the potentiometer from reaching its expected physical range.

1. 1

   Secure the Machine

   Park the tractor on a level surface, engage the parking brake, and ensure all pressure is relieved from hydraulic circuits before removing covers or valves.

2. 2

   Repair Wiring

   If the diagnostic checks revealed frayed wires, poor pin connections, or shorts in the transmission harness, repair or replace the affected wiring.

3. 3

   Replace the Potentiometer

   If the wiring is intact but the signal remains out of range (or the sensor is physically damaged), locate the F2/R1 synchronizer potentiometer on the transmission housing and replace it.

4. 4

   Inspect Driveline

   If a new potentiometer does not resolve the out-of-range signal, the transmission driveline must be inspected for mechanical faults, such as a damaged clutch or a jammed synchronizer assembly.

5. 5

   Recalibrate the Transmission

   After repairing the wiring or replacing the potentiometer, you must perform a transmission calibration using the H-Menu or an electronic service tool so the Transmission Controller can learn the new potentiometer limits.