New Holland 5061 – UCM: Port Lock Valve (On/Off) Solenoid Supply Open Circuit Red

The Universal Control Module (UCM) has detected an open circuit in the electrical supply to the loader port lock solenoid. This solenoid is a safety feature that hydraulically locks the loader's lift and tilt functions. A disruption in this circuit prevents the solenoid from actuating, causing the system to default to a locked state and disabling the loader arms and bucket as a fail-safe measure.

• L140
• L150
• L160
• L170
• L180
• L185
• L190
• L213
• L215
• L218
• L220
• L221
• L223
• L225
• L228
• L230
• L465
• L565
• L865
• LS140
• LS150
• LS160
• LS170
• LS180
• LS180.B
• LS185.B
• LS190
• LS190.B
• LX465
• LX485
• LX565
• LX665
• LX865
• LX885
• LX985
• C185
• C190
• C227
• C232
• C238

1. 1

   Visually inspect the wiring harness leading to the Port Lock Valve Solenoid for chafing, cuts, corrosion, or loose connectors.

2. 2

   Disconnect the Port Lock Valve Solenoid connector (often labeled X-PORT_LK) and inspect the pins and sockets for corrosion, dirt, or damage.

3. 3

   Perform a solenoid resistance test using a multimeter across the solenoid pins (expected range is typically 20-60 ohms; a reading of 'OL' indicates an internal open circuit).

4. 4

   Test wiring harness continuity between the UCM connector and the solenoid connector to check for broken wires.

5. 5

   Check for voltage at the solenoid connector with the key on; the supply pin should show battery voltage against a good chassis ground.

1. 1

   Isolate the fault

   Based on the diagnostic checks, determine if the open circuit is located in the solenoid coil, the wiring harness, or a connector.

2. 2

   Replace the solenoid

   If the solenoid tests open (infinite resistance), relieve all hydraulic pressure, unscrew the old solenoid from the valve block, and install the new solenoid with correct O-rings/seals. Torque to manufacturer specifications.

3. 3

   Repair wiring harness

   If a break is found in the wiring harness or a lack of supply voltage is detected, repair or replace the damaged section. Seal repairs against moisture and protect from abrasion.

4. 4

   Clear Fault Codes

   After the repair is complete, reconnect the battery, start the machine, and clear the fault codes using the machine's diagnostic interface or a compatible service tool.

5. 5

   Verify Operation

   Operate the machine and the associated hydraulic function to ensure the fault code does not return and the system functions correctly.