Case IH 520206-22 - VCM – VCM / UCM (Steering Valve Controller): Steering valve controller roading switch voltage missing at power-up / Fault in the circuit of the roading switch

This fault indicates that the controller managing the automated steering system is not detecting the expected voltage from the master roading switch circuit during the tractor's power-up sequence. If the voltage is missing or the circuit is open/faulty, the controller cannot verify the state of the switch. As a safety precaution, the system will lock out the autoguidance features and log this fault.

• MAGNUM AFS Connect
• Case IH AFS Connect Magnum (Models 180, 200, 220, 240, 250, 280, 310, 340, 380)
• Case IH Steiger / Quadtrac (Models 335, 385, 435, 485, 535, 620)
• Case IH Puma
• Case IH Optum

1. 1

   Manually toggle the roading switch on and off, then restart the tractor to see if the fault clears

2. 2

   Check the ISOBUS diagnostic page on the Pro 1200 or AFS Pro display to verify if the display recognizes the switch state changing

3. 3

   Inspect the cab fuse panel for any blown fuses related to the cab switches, VCM, or steering valve controller

4. 4

   Using a multimeter, check for 12V power at the roading switch connector when the key is turned ON

5. 5

   Inspect the wiring harness between the headliner/console roading switch and the Steering Valve Controller for pinched wires, rodent damage, or loose connector pins.

1. 1

   Disconnect power

   Turn off the tractor and disconnect the battery to prevent electrical shorts.

2. 2

   Access the switch

   Remove the trim panel on the headliner or upper console to access the back of the roading switch.

3. 3

   Test switch continuity

   Disconnect the wiring harness from the switch. Use a multimeter set to ohms/continuity to test the switch terminals. Toggle the switch; if the multimeter does not show a change in continuity, the internal contacts have failed, and the switch must be replaced.

4. 4

   Check the harness

   If the switch tests good, use the multimeter to check the continuity of the wires running from the switch connector down to the VCM/Steering Valve Controller harness.

5. 5

   Repair wiring

   Repair any broken wires or replace damaged terminal pins (e.g., if corrosion is present at the connector).

6. 6

   Reassemble and clear codes

   Plug the switch back in, reinstall the trim panels, and reconnect the battery. Turn the key ON and verify that the fault code 520206-22 changes from Active to Inactive or clears entirely.

7. 7

   Software update

   If the switch and wiring are perfectly intact, the Steering Valve Controller (SVC) may require a software re-flash (e.g., updating to software version 2.02) by a Case IH dealer.