New Holland UCM 5261 – UCM: Bucket Rollback / Dump: Solenoid Dump (B) Supply Open Circuit

The control module has detected a break in the electrical circuit (an open circuit) supplying power to the "Dump B" directional solenoid on the loader bucket control valve. Because the circuit is open, the solenoid cannot energize, which will likely result in the loss of the bucket dump function.

• L213
• L215
• L218
• L220
• L223
• L225
• L230
• C227
• C232
• C238
• B90B
• B100B
• B115B
• SR175
• SV185
• TR270

1. 1

   Inspect the wiring harness routing from the UCM to the hydraulic control valve block for chafed wires, rodent damage, or pinched harnesses near the loader arm pivot points.

2. 2

   Disconnect the harness at the Bucket Dump (B) Solenoid and inspect the pins for corrosion, moisture, or pushed-back terminals.

3. 3

   Perform a coil resistance test by measuring the resistance across the two pins of the Dump (B) solenoid coil with a multimeter. An 'OL' (Open Loop) or infinite resistance reading indicates the solenoid coil has failed internally.

4. 4

   Perform a harness continuity test by disconnecting the harness at the UCM and measuring continuity between the UCM output pin for the Dump B supply and the solenoid connector. An 'OL' reading indicates a broken wire in the harness.

1. 1

   Safely Park the Machine

   Lower the loader arms and bucket completely to the ground to relieve hydraulic pressure. Turn off the engine and engage the parking brake.

2. 2

   Disconnect Power

   Turn off the battery disconnect switch or disconnect the negative battery cable to prevent electrical shorts during repair.

3. 3

   Access the Control Valve

   Open the cab or access panels to reach the main hydraulic directional control valve block.

4. 4

   Repair Wiring

   If the diagnostic checks revealed a broken wire, splice and solder the wire using heat-shrink tubing to ensure a weather-tight seal.

5. 5

   Replace the Solenoid

   Clean the area around the Dump (B) solenoid to prevent dirt from entering the hydraulic system. Remove the retaining nut holding the solenoid coil to the valve stem. Slide the old solenoid coil off the valve cartridge. Slide the new OEM solenoid onto the cartridge and tighten the retaining nut to the specified torque in your service manual.

6. 6

   Reassemble and Test

   Reconnect the electrical harness to the solenoid. Reconnect the battery. Turn the key on and clear the UCM fault codes using a diagnostic tool or the dash display. Start the machine and test the bucket rollback and dump functions to verify the repair.