Case IH 4742 – Universal Control Module (UCM): Left Swash Plate Angle Sensor Pin A Shorted To Power

The control module detects abnormally high voltage on Pin A of the left swash plate angle sensor circuit. This is typically caused by the sensor's signal or ground wire (Pin A) rubbing against a 12V or 5V power source wire, a damaged wiring harness, or an internal short within the sensor itself.

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

1. 1

   Visually inspect the wiring harness leading to the Left Swash Plate Angle Sensor for chafed wires, melted insulation, or pinched harnesses.

2. 2

   Disconnect the sensor, turn the ignition ON (engine off), and use a multimeter to probe Pin A on the machine-side harness connector for battery voltage (12V) or a 5V reference to check for a harness short.

3. 3

   If the harness tests normal, test the sensor for an internal short.

1. 1

   Prepare the Machine

   Park the machine on a level surface, lower the loader arms completely, turn off the engine, and disconnect the negative battery cable.

2. 2

   Access the Pump

   Lift the cab or open the service panels to access the hydrostatic drive pumps. Locate the left-side drive pump.

3. 3

   Remove the Sensor

   Disconnect the electrical connector from the Left Swash Plate Angle Sensor. Remove the mounting bolts or unscrew the sensor from the pump housing (be prepared for minor hydraulic fluid seepage; cap the port if necessary).

4. 4

   Repair Wiring (If Applicable)

   If your diagnostics pointed to a harness issue, splice and repair the shorted wires on Pin A using weather-sealed heat shrink connectors, or replace the affected harness section.

5. 5

   Install New Sensor

   If the sensor is internally shorted, install the replacement sensor into the pump housing and torque to OEM specifications.

6. 6

   Reassembly

   Reconnect the electrical connector. Reconnect the battery.

7. 7

   Calibration

   Turn the key ON. Use the Case IH Electronic Service Tool (EST) to clear the inactive 4742 fault code and run a hydrostatic pump calibration routine so the UCM can learn the new sensor's neutral, minimum, and maximum voltage ranges.