New Holland UCM 1909 – UCM: Power Supply: Rail 12VF3 - Boom Raise / Lower Input Power OFF

The control module has detected that the internal 12-volt power supply rail (designated as 12VF3) which provides power to the boom raise and lower input circuits is turned off or has failed. This typically happens when there is a short to ground in the boom control circuit causing the module to shut down the rail to protect itself, or if the module has suffered an internal failure.

• L213
• L216
• L218
• L220
• L221
• L223
• L225
• L228
• L230
• L234
• L316
• L318
• L320
• L323
• L325
• C227
• C232
• C234
• C237
• C238
• C245

1. 1

   Inspect the main fuse box and test the UCM/VCM relay (K003) and main power relay to ensure the module is receiving proper voltage.

2. 2

   Check the wiring harness running from the UCM to the boom raise/lower joystick/controls for rubbed wires, pinched harnesses, or exposed copper shorting to the frame.

3. 3

   Disconnect the boom control inputs and check for internal shorts within the joystick or switches.

4. 4

   Test the UCM internal resistance (0 ohms indicates an internal short, infinite/high resistance indicates an internal open) if external wiring is intact.

1. 1

   Lower boom and turn off machine

   Lower the boom to the ground and turn off the machine.

2. 2

   Disconnect battery

   Disconnect the negative battery cable to prevent electrical arcing or further module damage.

3. 3

   Locate UCM/VCM

   Locate the UCM/VCM (typically located in the cab or under the cab depending on the specific model year).

4. 4

   Disconnect wiring harnesses

   Carefully disconnect the multi-pin wiring harness connectors from the UCM.

5. 5

   Remove UCM

   Unbolt the UCM from its mounting bracket and remove it from the machine.

6. 6

   Install new UCM

   Install the new or remanufactured UCM and secure the mounting hardware.

7. 7

   Reconnect wiring harnesses

   Reconnect the wiring harnesses, ensuring the connectors are fully seated and locked.

8. 8

   Reconnect battery

   Reconnect the negative battery cable.

9. 9

   Program and calibrate UCM

   A new or remanufactured UCM will not work out of the box. It must be flashed/programmed with the specific machine's software and calibrated by an authorized New Holland dealer using the Electronic Service Tool (EST).