New Holland UCM 5232 – UCM: Boom Raise/Lower: Solenoid Lower (B) Supply Short to Ground

The control module has detected a short circuit to ground on the electrical supply line that powers the solenoid responsible for lowering the boom/loader arm. This means the voltage intended to activate the solenoid is escaping directly to the chassis ground, typically caused by damaged wiring insulation touching the machine's metal frame or an internal short within the solenoid coil itself.

• L-Series (L140, L150, L160, L170, L175, L180, L185, L190)
• 200 Series (L213, L218, L220, L225, L228)
• C-Series Track Loaders (C175, C185, C190)
• Older LS and LX Series (LS140-LS190, LX465-LX985)
• Case Alpha series (SR and TR series)

1. 1

   Ensure the boom is fully lowered to the ground or resting securely on mechanical boom locks before inspecting the hydraulic control valve

2. 2

   Visually inspect the main hydraulic control valve and trace the wiring harness from the Boom Lower Solenoid (Solenoid B) back to the UCM, looking for pinched wires, melted insulation, or rubbing against the chassis

3. 3

   Perform a harness continuity test by disconnecting the solenoid and UCM connectors, then using a multimeter to check for continuity between the solenoid supply wire and chassis ground

4. 4

   Test the solenoid coil by measuring resistance between the solenoid's power terminal and its outer metal casing to check for an internal short to ground

1. 1

   Disconnect battery

   Turn off the machine and disconnect the negative battery cable to prevent electrical spikes.

2. 2

   Repair wiring harness

   If the wiring is shorted: Cut out the damaged section of the wire. Splice in a new section of wire using weather-sealed (heat-shrink) butt connectors. Wrap the repaired section in protective wire loom and secure it with zip ties away from moving parts or sharp edges.

3. 3

   Replace solenoid coil

   If the solenoid is shorted: Thoroughly clean the area around the hydraulic control valve to prevent dirt from entering the hydraulic system. Remove the retaining nut or bolt at the end of the solenoid cartridge. Slide the faulty solenoid coil off the valve stem. Slide the new solenoid coil onto the stem, ensuring any O-rings or magnetic spacers are oriented correctly. Reinstall and tighten the retaining nut to the manufacturer's specified torque (do not overtighten).

4. 4

   Reconnect solenoid

   Reconnect the electrical connector to the solenoid.

5. 5

   Reconnect battery

   Reconnect the negative battery cable.

6. 6

   Clear code and test

   Turn the key on and use the electronic service tool (or the machine's diagnostic display) to clear the UCM 5232 code. Test the boom lower function to verify the repair.