Case IH 4735 – UCM (Universal Control Module): Right Swash Plate Angle Sensor Pin B Shorted To Power

The control module has detected an abnormally high voltage (a short to power) on the Pin B circuit of the sensor that monitors the angle of the right-hand hydrostatic pump's swash plate.

• skid steer
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• TR270
• TV380
• L218
• L220
• C227
• C232

1. 1

   Turn the ignition switch OFF and disconnect the UCM connector (X-CN3A).

2. 2

   Measure the resistance between the sensor's signal pin at the UCM harness (X-CN3A pin 25) and chassis ground. The resistance should be less than 10 Ω.

3. 3

   Wiggle the wiring harness during the resistance measurement to reveal any intermittent shorts to power or ground.

4. 4

   With the cluster power ON but the engine OFF, supply 5V power to the sensor. Back-probe pins 3 and 4 of the sensor connector. A properly functioning and centered sensor should read approximately 2.5 volts on both pins. If Pin B is receiving full system voltage, the harness is shorted to a power source and must be repaired.

1. 1

   Preparation

   Ensure the machine is parked safely, the engine is off, and the battery is disconnected.

2. 2

   Locate the Sensor

   Locate the right swash plate angle sensor on the right-hand hydrostatic pump.

3. 3

   Removal

   Disconnect the electrical connector. Remove the mounting bolts securing the sensor to the pump housing and carefully pull the sensor out.

4. 4

   Installation

   Insert the new swash plate angle sensor. Crucial Note: Ensure the machined section of the swash plate angle sensor shaft faces the center of the hydrostatic pump. Improperly installing the sensor with the shaft facing outward will make it difficult to install the mounting bolts and will destroy the sensor seal.

5. 5

   Secure

   Install and tighten the mounting bolts.

6. 6

   Calibration/Adjustment

   Reconnect the battery and turn the cluster power ON (engine OFF). Back-probe pins 3 and 4. Rotate the sensor housing slightly until you read exactly 2.5 volts across the pins to ensure it is perfectly centered before final tightening.

7. 7

   Clear Codes

   Reconnect the harness, start the machine, and clear the UCM fault codes to verify the repair.