Case IH 5251 – UCM (Universal Control Module): Loader Bucket Valve (Directional) Solenoid Rollback (A) Supply Open Circuit

The control module has detected a break (open circuit) in the electrical supply line to the solenoid responsible for the loader bucket's rollback function, preventing the bucket from rolling back when commanded by the joystick.

• skid steer
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• tractors

1. 1

   Visually inspect the loader bucket directional control valve and the electrical connector at the Rollback (A) solenoid for disconnected plugs, severe corrosion, or pushed-out pins.

2. 2

   Perform a solenoid coil resistance test by disconnecting the harness and measuring across the pins with a multimeter. A healthy coil reads around 9 ohms; 'OL' indicates a broken internal coil.

3. 3

   Test harness continuity between the solenoid connector and the corresponding pin on the UCM harness. Look for pinch points or chafed wires along the loader arm routing.

4. 4

   Perform a UCM output test by turning the key ON (engine off) and commanding a rollback function with the joystick to verify voltage at the solenoid connector.

1. 1

   Secure the Machine

   Park the machine on a level surface. Lower the loader arms completely to the ground. If the arms must be raised for access, you must engage the mechanical lift arm support strut.

2. 2

   Relieve Hydraulic Pressure

   Turn the engine off. Turn the key back to the ON position (without starting) and cycle the joystick in all directions to relieve residual hydraulic pressure in the implement lines. Turn the key OFF.

3. 3

   Locate the Solenoid

   Access the main hydraulic control valve block and identify the Bucket Rollback (A) solenoid.

4. 4

   Remove the Faulty Component

   Disconnect the electrical connector. Remove the retaining nut at the end of the solenoid stem. Slide the faulty solenoid coil off the valve cartridge. (Note: If replacing the entire cartridge valve, thoroughly clean the area first, then unscrew the cartridge from the valve block).

5. 5

   Install the New Part

   Slide the new solenoid coil onto the valve stem and secure it with the retaining nut. Do not overtighten, as this can distort the coil.

6. 6

   Reconnect and Test

   Plug the electrical harness back in. Start the machine, clear the inactive fault codes from the UCM, and test the bucket rollback function to ensure smooth operation.