Case IH 5291 – UCM: Loader Auxiliary Valve (Directional) Solenoid Reverse (B) Supply Open Circuit

The control module has detected an open circuit on the power supply line to the Reverse (B) directional solenoid on the loader's auxiliary hydraulic valve.

• skid steer
• Skid Steer Loaders (SSL)
• Compact Track Loaders (CTL)
• 450
• 40XT
• 60XT
• 70XT
• 85XT
• 90XT
• 95XT
• 410
• 420
• 430

1. 1

   Inspect the wiring harness running from the UCM to the auxiliary hydraulic valve block for chafed, pinched, or severed wires.

2. 2

   Disconnect the plug at the Reverse (B) solenoid and check for water intrusion, corrosion, or pins that have pushed back out of the plastic connector housing.

3. 3

   Using a digital multimeter, measure the resistance across the pins of the Reverse (B) solenoid coil. An 'OL' (infinite resistance) reading indicates the internal coil is broken/open.

4. 4

   If the solenoid tests within normal resistance specs, test the continuity of the supply wire from the UCM harness connector down to the solenoid connector to isolate the break in the wiring.

1. 1

   Safety First

   Park the machine on a level surface, lower the loader arms completely, turn off the engine, and cycle the hydraulic controls to relieve any residual system pressure.

2. 2

   Locate the Valve

   Access the main loader control valve block (usually located under the cab).

3. 3

   Identify the Solenoid

   Locate the specific solenoid for the Auxiliary Valve Reverse (B) function.

4. 4

   Disconnect and Remove

   Unplug the electrical connector. If the diagnostic tests proved the coil is dead, remove the retaining nut holding the solenoid coil to the valve stem.

5. 5

   Replace the Solenoid

   Slide the old coil off the valve cartridge. Slide the new OEM replacement coil onto the stem and torque the retaining nut to the manufacturer's specification (do not overtighten, or you may distort the valve spool).

6. 6

   Repair Wiring (If Applicable)

   If the coil was good but the harness was broken, splice and heat-shrink the broken supply wire, or replace the damaged connector pigtail.

7. 7

   Test

   Reconnect the harness, turn the key on, and clear the UCM fault codes using a diagnostic tool or the cab display. Start the machine and function-test the auxiliary hydraulics in both directions to ensure the code does not return.