New Holland UCM 5505 – UCM: Bucket Rollback / Dump: Sensor Short to Power

This fault code indicates that the Bucket Valve Spool Sensor (which monitors the position of the spool valve controlling the bucket rollback and dump functions) is experiencing a "Short to Power" condition. The system is detecting a higher-than-expected voltage on the sensor's signal circuit, which usually points to a wiring issue or an internal failure of the sensor itself.

• L213
• L215
• L216
• L218
• L220
• L221
• L223
• L225
• L228
• L230
• L234
• C227
• C232
• C234
• C238

1. 1

   Visual Inspection: Locate the Bucket Valve Spool Sensor on the main hydraulic control valve. Inspect the sensor's pigtail and the main wiring harness for pinched wires, rubbed insulation, or melted areas that could cause the signal wire to short against a 12V or 5V power supply wire.

2. 2

   Connector Check: Disconnect the sensor and inspect the pins for corrosion, water intrusion, or bent terminals.

3. 3

   Circuit Testing: Using a multimeter, check the signal wire between the sensor connector and the UCM for continuity to power. If voltage is present on the signal wire while the sensor is unplugged (and the key is ON), the short to power is in the wiring harness.

4. 4

   Sensor Testing: If the wiring harness tests good, the short to power is likely an internal failure within the spool position sensor itself.

1. 1

   Disconnect Power

   Turn off the machine and disconnect the negative battery cable (or use the battery disconnect switch if equipped) to prevent electrical spikes.

2. 2

   Access the Control Valve

   Lift and secure the cab or open the access panels required to reach the main hydraulic control valve block.

3. 3

   Remove the Sensor

   Disconnect the electrical connector from the faulty Bucket Valve Spool Sensor. Unthread/remove the sensor from the control valve housing.

4. 4

   Install the New Sensor

   Install the replacement spool position sensor into the valve block.

5. 5

   Reconnect

   Plug the electrical connector back into the sensor, ensuring the locking tab clicks into place. Reconnect the battery.

6. 6

   Clear Codes and Test

   Use a diagnostic tool or DTC eraser to clear the UCM 5505 code. Start the machine and operate the bucket rollback and dump functions to verify smooth operation and ensure the code does not return.