New Holland UCM 4744 – UCM (Universal Control Module): Ground Drive: Pin B Short to Ground / Open Circuit

The Universal Control Module (UCM) has detected an electrical fault—either an open circuit or a short to ground—on Pin B of the left-hand swash plate angle sensor.

• L213
• L215
• L218
• L220
• L223
• L225
• L230
• C227
• C232
• C238

1. 1

   Trace the wiring harness from the UCM to the Left Hand Swash Plate Sensor for signs of abrasion, corrosion, or physical damage.

2. 2

   Disconnect the sensor and inspect the connector pins to ensure they are secure, tight, and free of corrosion or moisture.

3. 3

   Using a multimeter, test Pin B on the sensor's harness connector for continuity to the UCM (to rule out an open circuit) and check for continuity to the chassis ground (to rule out a short to ground).

4. 4

   Perform a swap test if the wiring tests good, as the sensor itself has likely failed internally.

1. 1

   Disconnect Power

   Always disconnect the battery before servicing the electrical or hydrostatic drive control systems.

2. 2

   Access the Pump

   Gain access to the hydrostatic drive pump assembly where the swash plate sensors are mounted.

3. 3

   Remove the Sensor

   Disconnect the wiring harness from the Left Hand Swash Plate Sensor. Remove the mounting screws and extract the sensor.

4. 4

   Install the New Sensor

   Seat the new Left Hand Swash Plate Sensor into position and secure it with the mounting screws. Reconnect the wiring harness.

5. 5

   Reconnect Power

   Reconnect the battery.

6. 6

   Calibrate the Ground Drive

   Perform a Ground Drive Calibration using the Electronic Service Tool (EST) or the instrument cluster setup mode.