New Holland UCM 5221 – UCM (Universal Control Module): Boom Raise/Lower: Solenoid Raise (A) Supply Open Circuit

The control module has detected a break in the electrical circuit (an "open circuit") supplying power to the "Raise" solenoid (Solenoid A) on the loader arm directional control valve. Because the circuit is open, the electrical signal cannot reach the solenoid, preventing the machine from raising the boom/loader arms.

• L213
• L215
• L218
• L220
• L223
• L225
• L230
• L316
• L318
• L320
• C227
• C232
• C238
• C327
• C337
• B90B
• B95D
• B100B
• B110D
• B115B

1. 1

   Inspect the electrical connector at the loader arm directional valve (Solenoid A) for disconnected plugs, backed-out pins, or heavy corrosion.

2. 2

   Trace the wiring harness from the UCM to the loader arm valve, looking for chafed, cut, or pinched wires that would cause a break in the supply line.

3. 3

   Perform a coil resistance test by disconnecting the harness from the Raise (A) solenoid and measuring resistance across the coil pins (an infinite/OL reading indicates internal failure).

4. 4

   Perform a voltage supply test at the harness-side connector with the key ON and the operator commanding a boom raise to verify the UCM is sending the signal.

1. 1

   Secure the Machine

   Safely lower the boom/loader arms to the ground. If the arms must be raised for access, you must secure them using the mechanical hydraulic cylinder lock / loader valve lock.

2. 2

   Disconnect Power

   Turn off the ignition and use the battery disconnect switch (or disconnect the negative battery cable) to prevent electrical spikes during repair.

3. 3

   Access the Valve

   Locate the loader arm directional control valve block (usually located under the cab or in the chassis belly, depending on the model).

4. 4

   Disconnect the Solenoid

   Unplug the electrical connector from the Raise (A) solenoid.

5. 5

   Repair or Replace

   If the wiring is broken: Repair the broken wire in the harness using OEM-approved weather-sealed connectors. If the solenoid coil failed the resistance test: Remove the retaining nut holding the coil to the valve stem, slide the old coil off, and install the new replacement coil.

6. 6

   Reassembly

   Reconnect the electrical plug, ensuring the locking tab clicks into place.

7. 7

   Test

   Reconnect the battery, power on the machine, and use the Electronic Service Tool (EST) or the in-cab display to clear the inactive UCM 5221 fault code. Test the boom raise function to confirm the repair.