Case IH 5061 – UCM (Universal Control Module): Port Lock Valve (On/Off) Solenoid Supply Open Circuit

The control module has detected an open circuit in the electrical supply line to the Port Lock Valve Solenoid. This means the electrical path is broken—preventing current from flowing to the solenoid coil.

• skid steer
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• SR-series (e.g., SR175)
• 400-series (e.g., 430, 450)

1. 1

   Visually inspect the Port Lock Valve Solenoid electrical connector for loose pins, moisture, or corrosion.

2. 2

   Trace the wiring harness back from the solenoid to the UCM, looking for chafed wires, pinch points, or rodent damage.

3. 3

   Perform a coil resistance test by disconnecting the solenoid plug and measuring resistance across the two pins with a multimeter (a reading of 'OL' or infinite resistance indicates a broken internal coil).

4. 4

   Perform a voltage test at the harness-side connector with the operator in the seat commanding the hydraulics to unlock to verify supply voltage from the UCM.

1. 1

   Relieve hydraulic pressure

   Lower the loader arms completely to the ground. Turn off the engine and cycle the joysticks/controls to relieve any residual hydraulic pressure.

2. 2

   Lift and secure cab

   Lift the cab (if required for access on your specific model) and secure it with the mechanical lock.

3. 3

   Locate solenoid

   Locate the Port Lock Valve Solenoid on the loader control valve assembly.

4. 4

   Disconnect connector

   Disconnect the electrical connector from the solenoid.

5. 5

   Remove retaining nut

   Remove the retaining nut at the end of the solenoid cartridge.

6. 6

   Remove faulty coil

   Slide the faulty solenoid coil off the valve stem/cartridge. (If the cartridge itself is leaking or damaged, it can be unscrewed and replaced, but an open circuit usually only requires replacing the electromagnetic coil).

7. 7

   Install new coil

   Slide the new solenoid coil onto the cartridge.

8. 8

   Install retaining nut

   Install and tighten the retaining nut. Caution: Do not overtighten the nut (max ~9 ft-lbs), as overtightening can distort the cartridge and cause the internal spool to bind.

9. 9

   Reconnect connector

   Reconnect the electrical connector.

10. 10

    Test and clear codes

    Lower the cab, start the machine, and clear the fault codes using the instrument cluster or EST diagnostic tool. Test the loader functions to ensure the port lock engages and disengages properly.