Case IH 5231 – UCM (Universal Control Module): Loader Arm Valve (Directional) Solenoid Lower (B) Supply Open Circuit

The machine's control system has detected a break in the electrical circuit that supplies power to the "Lower" (B) directional solenoid on the loader arm control valve. An "open circuit" typically points to a disconnected electrical plug, a severed or chafed wire in the harness, or a failed (internally broken) solenoid coil.

• skid steer
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• SR130
• SR150
• SR175
• SR200
• SR220
• SR250
• SV185
• SV250
• SV300
• TR270
• TR320
• TV380

1. 1

   Visually inspect the loader arm directional control valve block and the electrical connector on the 'Lower' (B) solenoid for disconnected plugs, backed-out pins, or heavy moisture/corrosion.

2. 2

   Perform a solenoid coil resistance test by disconnecting the harness and measuring resistance across the pins. An 'OL' (Open Loop) reading indicates a broken internal winding.

3. 3

   Test harness continuity between the UCM and the solenoid on both supply and return wires, checking for chafing or breaks at pinch points along the boom and chassis.

4. 4

   Perform a voltage supply test with the key ON and hydraulic system enabled. Probe the supply wire at the solenoid connector while commanding a 'Lower' action to verify UCM voltage output.

1. 1

   Safety First

   Lower the loader arms completely to the ground. If the arms are stuck in the raised position, secure them with approved mechanical cylinder lockouts. Turn off the machine, remove the key, and disconnect the negative battery cable to prevent accidental short circuits.

2. 2

   Access the Valve Block

   Open the cab or remove the necessary access panels (depending on your specific model) to reach the main hydraulic control valve block.

3. 3

   Locate the Solenoid

   Identify the directional control valve for the loader arm and locate the specific solenoid designated for the "Lower" (B) function.

4. 4

   Remove the Faulty Component

   Disconnect the electrical connector. If only the coil is faulty, remove the retaining nut at the end of the valve stem and slide the coil off. (Note: If the entire cartridge valve needs replacing, clean the surrounding area thoroughly before unscrewing the cartridge to prevent dirt from entering the hydraulic system).

5. 5

   Install the New Part

   Slide the new solenoid coil onto the valve stem and tighten the retaining nut to the manufacturer's specified torque (do not overtighten, or you may distort the cartridge).

6. 6

   Reassemble

   Reconnect the electrical harness, ensuring the weather-pack seal clicks into place. Reconnect the battery.

7. 7

   Test and Clear Codes

   Turn the key ON, use your diagnostic tool (EST) to clear the 5231 fault code. Enable the hydraulics and test the loader arm raise/lower functions to verify the repair.