Case IH 1907 – VCM / UCM: VCM - Rail 12VF1 - Aux Retract Input Power Off

This code indicates a power supply failure or open circuit on the 12-volt rail (12VF1) that supplies power to the Auxiliary Retract input circuit. The controller has detected that the electrical power to the auxiliary hydraulic retract solenoid or its associated input circuit has been unexpectedly cut or disconnected.

• skid steer
• SR130
• SR150
• SR175
• SV185
• SR200
• SR220
• SR250
• SV300
• TR270
• TR310
• TR320
• TV370
• TV380

1. 1

   Verify the battery is fully charged and the battery master disconnect switch (if equipped) is functioning correctly, as voltage drops can trigger false UCM rail codes.

2. 2

   Check the main fuse box for blown fuses or a failing UCM Power Relay (specifically the relays providing power to the UCM/VCM rails).

3. 3

   Locate the wiring harness for the Auxiliary Retract circuit (often labeled X-AUX_RET in Case schematics). Inspect the harness routing from the UCM to the hydraulic control valve block for chafing, pinched wires, or melted insulation.

4. 4

   Disconnect the plug at the Auxiliary Retract Solenoid (located on the main EH control valve block). Check for water intrusion, bent pins, or corrosion.

5. 5

   Use a multimeter to measure the resistance across the Auxiliary Retract Solenoid coil. If it reads as an open circuit (infinite resistance) or a dead short, the solenoid is the culprit.

6. 6

   Back-probe the 12VF1 circuit at the UCM connector to verify if the module is actually outputting 12V to the circuit when the auxiliary retract function is commanded.

1. 1

   Safely Secure the Machine

   Lower the loader arms to the ground, turn off the engine, and engage the parking brake.

2. 2

   Disconnect Power

   Turn off the battery quick disconnector or disconnect the negative battery cable to prevent electrical shorts during repair.

3. 3

   Access the Control Valve

   Lift the cab or open the rear/top access panels (depending on the specific model) to gain access to the main electro-hydraulic (EH) control valve block.

4. 4

   Replace the Solenoid (If faulty)

   If diagnostic tests proved the Auxiliary Retract Solenoid is dead, disconnect its electrical plug, unscrew the retaining nut, and slide the old solenoid coil off the valve stem. Install the new solenoid coil, tighten the nut to OEM torque specs, and reconnect the harness.

5. 5

   Repair the Harness (If faulty)

   If the wiring was chafed (a common issue on skid steers due to vibration), cut out the damaged section of the X-AUX_RET wire and solder/heat-shrink a new section of wire, or replace the affected harness section.

6. 6

   Replace the UCM/VCM (Last resort)

   If the wiring and solenoid are perfect but the 12VF1 rail is dead internally, the UCM must be replaced. Note: A new UCM will require programming/flashing with the machine's specific configuration and serial number using the CNH Electronic Service Tool (EST).

7. 7

   Reassemble and Clear Codes

   Reconnect the battery, power on the machine, and use the EST to clear the 1907 fault code. Test the auxiliary hydraulic retract function to confirm the repair.