Case IH 4752 – UCM (Universal Control Module): Left Swash Plate Angle Sensor - Command Does not Match Swash Plate Angle

The control module is commanding the left hydrostatic drive pump's swash plate to move to a specific angle, but the feedback signal from the left swash plate angle sensor indicates that the swash plate has not reached the commanded position.

• skid steer
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• Puma
• Steiger
• Maxxum

1. 1

   Check for related electrical codes (4741, 4742, 4744, 4745, and 4747) that indicate a direct circuit failure (short-to-ground, short-to-power, or open-circuit) on Pins A or B of the Left Swash Plate Angle Sensor. If present, diagnose the wiring harness issue first.

2. 2

   Inspect the wiring harness and connector located underneath the left hydrostatic travel pump for rubbing, corrosion, or breaks.

3. 3

   Verify that the swash plate mechanism inside the pump is not physically stuck or binding due to internal mechanical failure.

4. 4

   Ensure the hydraulic system has adequate charge/pilot pressure to physically stroke the swash plate.

1. 1

   Preparation

   Park the machine on a level surface, lower all loader arms/attachments to the ground, engage the parking brake, and turn off the engine. Allow the hydraulic system to cool and relieve any residual pressure.

2. 2

   Locate the Sensor

   Follow the hydraulic lines from the left drive motor to the left hydrostatic tandem pump. The swash plate angle sensor is mounted to the pump housing (often on the bottom).

3. 3

   Disconnect

   Carefully unplug the electrical harness connector from the sensor.

4. 4

   Remove the Sensor

   Remove the mounting screws holding the sensor to the pump housing. (Note: replacement screws are not supplied with the new sensor and must be reused or procured locally). Pull the sensor straight out.

5. 5

   Install the New Sensor

   Insert the new sensor, ensuring that the mechanical feedback linkage/pin aligns correctly with the swash plate mechanism inside the pump.

6. 6

   Secure

   Reinstall the mounting screws and tighten them to the OEM torque specification. Reconnect the electrical harness.

7. 7

   Calibration

   Connect the Case IH Electronic Service Tool (EST). Clear the inactive fault codes and perform a hydrostatic pump calibration to allow the UCM to learn the new sensor's zero-angle and maximum-angle positions.