Case IH 1913 – VCM / UCM: VCM - Rail 12VS1 - Bucket Curl Input Power Off

The control module is detecting that the power supply voltage to the bucket curl input circuit (Rail 12VS1) is off, below the operational limit, or experiencing a fault.

• skid steer
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• SR130
• SR150
• SR160
• SR175
• SR200
• SR210
• SR220
• SR240
• SR250
• SV185
• SV250
• SV280
• SV300
• SV340
• TR270
• TR310
• TR320
• TR340
• TV370
• TV380

1. 1

   Check fuses and relays related to the bucket curl, auxiliary hydraulics, and the VCM/UCM power supply (specifically the 12VS1 circuit).

2. 2

   Visually inspect the wiring harness running from the VCM/UCM to the bucket curl control switch (joystick) and hydraulic solenoids for chafed wires, pinched lines, or disconnected/corroded pins.

3. 3

   Test the bucket curl switch/joystick button for proper continuity and operation.

4. 4

   Using a multimeter, measure the voltage at the bucket curl input pin on the VCM/UCM connector to verify the module is receiving the correct 12V power supply.

1. 1

   Disconnect Power

   Always disconnect the battery before servicing electrical components or the VCM/UCM.

2. 2

   Replace Fuses/Relays

   If a blown fuse or bad relay was found during diagnostics, replace it with a new one of the exact same amperage/rating. Reconnect the battery and test the bucket curl function to see if the code clears.

3. 3

   Repair Wiring

   If the harness is damaged, repair the broken wires using proper soldering and heat-shrink tubing, or replace the affected harness section entirely.

4. 4

   Replace the Switch/Joystick

   If the joystick switch failed the continuity test, replace the joystick handle or the specific switch assembly.

5. 5

   Replace the VCM/UCM

   If the fuses, relays, wiring, and switches are all in good working order, the VCM/UCM itself has likely suffered an internal failure on the 12VS1 rail. Remove the mounting bracket hardware, disconnect the multi-pin connectors, and install a new VCM/UCM. Note: A replacement VCM/UCM will need to be flashed/reprogrammed by an authorized dealer using the EST (Electronic Service Tool) before the machine will operate correctly.