New Holland UCM 5262 – UCM: Bucket Rollback / Dump: Solenoid Dump (B) Supply Short to Ground

The control module has detected that the electrical supply circuit providing power to the 'Dump (B)' solenoid on the bucket's directional control valve has shorted to ground. This prevents the solenoid from receiving the proper voltage to actuate, meaning the machine will likely be unable to perform the bucket dump function.

• L213
• L215
• L216
• L218
• L220
• L223
• L225
• L228
• L230
• C227
• C232
• C238
• B90B
• B100B
• B115B

1. 1

   Visual Inspection: Inspect the wiring harness running from the UCM to the loader bucket directional control valve. Look for chafed wires, melted insulation, or pinch points where the wire might be touching the machine's chassis (ground).

2. 2

   Connector Check: Disconnect the electrical connector at the Dump (B) solenoid. Inspect the pins for corrosion, moisture, or bent terminals that could be bridging the supply pin to the ground pin.

3. 3

   Harness Short-to-Ground Test: With the battery disconnected and the UCM and solenoid unplugged, use a multimeter to check for continuity between the solenoid supply wire and a known good chassis ground. If continuity exists, the wiring harness is shorted and must be repaired.

4. 4

   Solenoid Coil Test: Measure the resistance across the pins of the Dump (B) solenoid itself, and from the supply pin on the solenoid to the solenoid housing. If the resistance is zero or out of specification (indicating an internal short to the casing), the solenoid is the culprit.

1. 1

   Secure the Machine

   Lower the loader arms and bucket flat to the ground. Turn off the engine and engage the parking brake.

2. 2

   Disconnect Power

   Turn the battery disconnect switch to the 'OFF' position or disconnect the negative battery cable to prevent electrical spikes.

3. 3

   Locate the Valve

   Access the main hydraulic control valve block (usually located under the cab or behind the access panels, depending on the model). Locate the specific directional valve section for the bucket dump/rollback function.

4. 4

   Disconnect the Solenoid

   Unplug the electrical connector from the Dump (B) solenoid.

5. 5

   Remove the Solenoid

   Remove the retaining nut holding the solenoid coil to the valve stem. Slide the faulty solenoid coil off the valve cartridge.

6. 6

   Install the New Solenoid

   Slide the replacement solenoid onto the valve stem. Thread the retaining nut back onto the valve body and tighten it securely.

7. 7

   Reconnect Wiring

   Plug the electrical connector back into the new solenoid. Ensure the locking tab clicks into place.

8. 8

   Restore Power and Test

   Reconnect the battery, turn the key on, and clear the inactive fault codes from the UCM. Start the machine and test the bucket dump function to verify the repair.