New Holland UCM 5241 – UCM: Boom Raise/Lower: Loader Arm Solenoid(s) Short to Power

The control module has detected a short circuit to a 12V power source on the electrical circuit that controls the directional valve solenoids responsible for raising and lowering the loader arm (boom).

• Skid Steer Loaders (SSL) (e.g., L218, L220, L175)
• Compact Track Loaders (CTL) (e.g., C232)
• Backhoe Loaders (e.g., B90B, B100B, B115B)

1. 1

   Trace the wiring harness from the UCM to the loader arm directional control valve block. Look for areas where wire insulation may have rubbed through against the chassis, causing a short to a 12V power supply wire.

2. 2

   Inspect the connectors at the UCM and at the boom valve solenoids (e.g., connector X-2SPD). Look for water intrusion, corrosion, or bent pins that could bridge the power and signal circuits.

3. 3

   Disconnect the loader arm solenoid and use a multimeter to measure the resistance across the coil pins to check for an internally shorted coil. A reading near zero ohms indicates the solenoid coil is internally shorted and must be replaced.

4. 4

   With the solenoid disconnected and the key ON (engine off), measure the voltage on the signal wire at the solenoid connector to check for a harness short. If it reads 12V when the boom function is not being commanded, the short to power is in the wiring harness.

1. 1

   Disconnect Power

   Turn off the machine and engage the battery quick-disconnect switch, or manually disconnect the negative battery cable to prevent electrical spikes.

2. 2

   Access the Valve Block

   Tilt the cab or remove the necessary access panels to reach the main hydraulic directional control valve block where the boom solenoids are mounted.

3. 3

   Repair Wiring

   If the diagnostic checks revealed a short in the harness, cut out the damaged section of wiring and splice in new wire using weather-sealed heat-shrink butt connectors. Secure the harness with zip ties away from pinch points.

4. 4

   Replace the Solenoid

   If the solenoid is internally shorted, disconnect the electrical plug from the faulty boom raise/lower solenoid, unscrew the retaining nut, slide the old coil off the valve cartridge, slide the new OEM solenoid coil onto the cartridge, and torque the retaining nut to the manufacturer's specification.

5. 5

   Reassemble and Test

   Reconnect the electrical plug to the solenoid. Reconnect the battery.

6. 6

   Clear Codes

   Use a diagnostic tool or DTC eraser to clear the UCM 5241 code from the module's memory. Start the machine and test the boom raise and lower functions to ensure the code does not return.