New Holland UCM 5243 – UCM: Boom Raise/Lower: Solenoids Return Open Circuit

The control module has detected a break in electrical continuity (an open circuit) on the return (ground) side of the boom directional valve solenoid circuit. The module is sending power to the solenoid to raise or lower the boom, but the electrical path is not completing its return to the controller.

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

1. 1

   Inspect the wiring harness routing from the UCM to the Boom Valve solenoids on the main hydraulic control valve block

2. 2

   Check the electrical connectors at the boom valve for disconnected plugs, backed-out pins, moisture, or corrosion

3. 3

   Use a multimeter to check the continuity of the return wire (ground side) between the solenoid connector and the UCM to isolate a broken wire

4. 4

   Measure the resistance of the boom valve solenoid coil itself. If the multimeter reads 'OL' (Open Loop) or infinite resistance, the coil has failed internally

1. 1

   Secure the Machine

   Park the machine on a level surface, lower the boom/loader arm completely to the ground to relieve hydraulic pressure, and turn off the engine.

2. 2

   Disconnect Power

   Disconnect the battery negative cable or turn the battery quick-disconnect switch to the "off" position to prevent electrical shorts during repair.

3. 3

   Locate the Valve

   Locate the Boom Directional Valve on the main hydraulic control valve bank.

4. 4

   Disconnect Solenoid

   Unplug the wiring harness connector from the affected boom raise/lower solenoid.

5. 5

   Repair Wiring

   If the diagnostic checks revealed a broken wire or corroded connector on the return circuit, repair the wiring harness or splice in a new connector pigtail.

6. 6

   Replace Solenoid

   If the solenoid coil tested open, remove the retaining nut holding the coil to the valve stem and slide the old coil off. Slide the new solenoid coil onto the stem and secure it with the retaining nut.

7. 7

   Reassemble and Test

   Plug the electrical connector back in. Reconnect the battery, turn the key on, and verify the UCM 5243 code is now inactive. Start the machine and test the boom raise and lower functions to confirm the repair.