New Holland UCM 1913 – UCM: Power Supply: Rail 12VS1 - Bucket Curl Input Power OFF

This code indicates a failure or interruption in the 12-volt power supply rail (12VS1) that specifically powers the bucket curl function. The system has detected that the electrical input power required to actuate the bucket curl solenoid is off, which typically points to an open circuit, a short to ground, a blown fuse, or an internal module failure.

• L213
• L216
• L218
• L220
• L221
• L223
• L225
• L230
• L318
• L320
• L323
• L325
• C227
• C232
• C238
• C327
• C332
• C338

1. 1

   Inspect the main fuse panel for any blown fuses related to the hydraulic controls or the UCM/VCM power supply.

2. 2

   Trace the wiring harness from the UCM to the main hydraulic control valve. Look for chafed wires, pinched lines, or disconnected plugs that could cause an open circuit or a short to ground on the 12VS1 rail.

3. 3

   Locate the bucket curl solenoid on the main hydraulic control valve block. Disconnect the harness and use a multimeter to check the solenoid coil for proper resistance. A dead short in the solenoid can cause the UCM to shut down the power rail to protect the circuit.

4. 4

   Verify that the right-hand joystick (which controls the bucket curl/dump functions) is sending the correct implausible state or command signals to the UCM.

5. 5

   Back-probe the UCM connector at the 12VS1 pin to see if the module is outputting 12 volts when the bucket curl is commanded. If there is no voltage leaving the UCM and the wiring/solenoid are good, the UCM has likely suffered an internal failure.

1. 1

   Disconnect Power

   Always turn off the machine and disconnect the negative battery cable before servicing the UCM or hydraulic electrical components.

2. 2

   Repair/Replace Wiring

   If the diagnostic checks revealed a broken or shorted wire between the UCM and the bucket curl solenoid, repair the wire using proper weather-sealed connectors, or replace the affected harness section.

3. 3

   Replace the Solenoid

   If the bucket curl solenoid failed the resistance test, remove the retaining nut on the hydraulic control valve, slide the old solenoid coil off the spool, and install a new OEM solenoid. Reconnect the wiring harness.

4. 4

   Replace the UCM

   If the 12VS1 rail inside the UCM is permanently damaged (internal memory or core monitoring fault): Disconnect the multi-pin connectors from the UCM. Unbolt the UCM from its mounting bracket and remove it. Install the new or remanufactured UCM and reconnect the harnesses.

5. 5

   Module Flashing

   If the UCM was replaced, the new module will be blank. A certified New Holland dealer must connect the Electronic Service Tool (EST) to flash the module with the correct software for your specific machine's PIN/serial number before it will operate.

6. 6

   Test Operation

   Reconnect the battery, start the machine, and test the bucket curl function to ensure the fault code is cleared and hydraulic operation is restored.