Case IH 3120 - UCM – ECM / UCM: PTO Twist Sensor - Not Plausible

The controller is receiving a signal from the PTO twist sensor (torque sensor) that is out of the expected range, erratic, or does not logically align with other inputs like engine speed and driveline data.

• MAXXUM T4E
• Magnum Series (180, 190, 210, 225, and 235–340 Series 4)
• Puma Series (155, 165, 180–260 CVX)
• Maxxum / MXM Series

1. 1

   Visual & Physical Inspection: Check if the PTO twist sensor is physically damaged or incorrectly installed on the transmission housing.

2. 2

   Wiring & Connector Check: Inspect the sensor's wiring harness and 3-pin connector (X-300 or X-262) for open circuits, short circuits to ground, or shorts to battery.

3. 3

   Mechanical Check: Inspect the driveline for mechanical binding or damage that could cause erratic torque readings.

4. 4

   Calibration Check: Determine if the sensor simply lost its calibration values (may be accompanied by code 3123).

1. 1

   Prepare tractor for calibration

   Ensure the tractor is parked safely. Switch off the air conditioning (if equipped) and ensure all electrical hydraulic applications are deselected.

2. 2

   Enter calibration mode

   Enter the tractor's transmission/UCM calibration mode.

3. 3

   Navigate to PTO twist calibration

   Navigate the menu until the display shows "Pt", which stands for PTO twist calibration.

4. 4

   Begin calibration

   Press and hold the downshift button to begin calibrating the PTO twist sensor.

5. 5

   Wait for successful calibration

   Continue holding the button. When the PTO twist sensor has been calibrated successfully, the display will alternate between "Pt" and the new calibration value.

6. 6

   Save calibration

   Release the downshift button to save the calibration. The display will change to the next calibration step (e.g., "A" for clutch A).