New Holland UCM 5281 – UCM (Universal Control Module): Aux Control Function: Solenoid Forward (A) Supply Open Circuit

This code indicates a fault in the electrical circuit controlling the forward auxiliary hydraulics. Specifically, the system has detected an "open circuit" on the supply line to the Auxiliary Forward (A) Solenoid. This means the electrical path is broken, which can be caused by a disconnected plug, a severed wire in the harness, or a failed (burnt out) solenoid coil.

• L213
• L215
• L218
• L220
• L221
• L223
• L225
• L228
• L230
• C227
• C232
• C234
• C237
• C238

1. 1

   Visually inspect the wiring harness leading to the Auxiliary Solenoid Forward (A) for cuts, chafing, or pinch points

2. 2

   Disconnect the electrical plug at the solenoid and check for loose, backed-out, or heavily corroded pins

3. 3

   Measure the resistance across the pins of the solenoid coil using a multimeter (infinite resistance or OL indicates an internal coil failure)

4. 4

   Check the continuity of the wiring harness between the solenoid connector and the UCM to locate any breaks in the wire

1. 1

   Park the machine on a level surface, lower the boom completely, and turn off the engine.

2. 2

   Turn the battery disconnect switch to the "OFF" position or disconnect the negative battery cable.

   This prevents electrical shorts.

3. 3

   Access the main hydraulic control valve block.

   Usually located under the cab.

4. 4

   Repair the broken wire using OEM-approved sealed connectors, or replace the damaged harness section.

   Perform this if the diagnostic tests pointed to a wiring issue.

5. 5

   Remove the retaining nut holding the coil to the auxiliary valve stem, slide the old coil off, and install the new replacement coil.

   Perform this if the solenoid coil failed.

6. 6

   Reconnect the electrical harness to the solenoid.

   Ensure the connector clicks and locks into place.

7. 7

   Reconnect the battery and turn the key on.

8. 8

   Clear the DTC (Diagnostic Trouble Code) from the UCM memory.

   Use the instrument cluster interface or an Electronic Service Tool (EST).

9. 9

   Start the machine and test the auxiliary hydraulic forward function to verify the repair.