Case IH 520210-29 - VCM – UCM / VCM: Cut-off solenoid stuck open

The system has detected that the steering valve cut-off solenoid is stuck in the open position. Specifically, the spool movement test failed during the transition from on-road to off-road mode.

• MAGNUM AFS Connect
• Magnum 250 AFS Connect
• Magnum 280 AFS Connect
• Magnum 310 AFS Connect
• Magnum 340 AFS Connect
• Magnum 380 AFS Connect
• Magnum 400 AFS Connect
• Optum
• Steiger

1. 1

   Verify the Mode Transition: Attempt to manually transition the tractor between on-road and off-road modes to see if the steering ratio/feel changes or if the error actively triggers during the spool movement test.

2. 2

   Electrical Inspection: Inspect the wiring harness and connector leading to the cut-off solenoid on the steering valve. Look for chafed wires, corrosion, or a short-to-ground that could be keeping the solenoid energized (open).

3. 3

   Mechanical Binding Check: Determine if the issue is electrical (the UCM is commanding it open or a short is present) or mechanical (the solenoid spool is physically jammed with debris).

1. 1

   Locate the Steering Valve

   Identify the main steering valve assembly (usually located under the cab/cowl area, connected to the steering column hydraulics).

2. 2

   Isolate the Cut-off Solenoid

   Locate the specific cut-off solenoid on the steering valve block responsible for the on-road/off-road circuit transition.

3. 3

   Remove and Inspect

   Depressurize the hydraulic system. Carefully remove the cut-off solenoid from the steering valve block.

4. 4

   Clean and Test

   Inspect the solenoid spool and the valve bore for metal shavings, debris, or scored metal. Clean the component thoroughly. You can bench-test the solenoid with a 12V source to see if the pintle actuates smoothly and closes fully when power is removed.

5. 5

   Replace Components

   If the solenoid is electrically dead or mechanically scored, replace the cut-off solenoid. If the bore inside the steering valve is heavily damaged, the entire steering valve assembly may need to be replaced.

6. 6

   Reassemble and Calibrate

   Reinstall the solenoid/valve, bleed the hydraulic steering circuit if necessary, and clear the UCM fault codes.

7. 7

   Verification

   Run the tractor and perform the on-road to off-road transition test via the AFS Pro monitor to ensure the spool movement test passes and code 520210-29 does not return.