Case IH 15255 – Steering Valve Controller (SVC) / Steering Redundant Controller (SRC): Roading switch state crosscheck between the steering valve main and safety controllers failed

There is a synchronization failure or data mismatch between the main steering valve controller and the redundant safety controller regarding the current position (open/closed) of the master roading switch. When the two controllers cannot agree on the switch's state, the system defaults to a safe state and disables automated steering.

• Steiger T4B
• Case IH Farmall Series (40, 45, 50, 115U)
• Case IH Magnum Series (180, 200, 220, 240, 250, 280, 310, 340, 380 AFS Connect)
• Case IH Steiger Series (335, 385, 435, 485, 535, 620)
• Case IH Vestrum CVX Series

1. 1

   Check for related electrical fault codes (e.g., 15252, 15253, 15254) that might pinpoint the issue

2. 2

   Manually toggle the master roading switch between the ON and OFF positions to see if the controllers re-synchronize and the error clears

3. 3

   Inspect the physical condition of the roading switch and trace its wiring harness back to the Steering Valve Controller for pinched wires, corrosion at connector pins, or loose grounds

4. 4

   Use a multimeter to verify that the roading switch is sending the correct voltage signals to the controller and is not stuck in a closed loop

1. 1

   Power Cycle & Reset

   Turn off the tractor, wait for the ECUs to power down completely, and turn the key back on. Toggle the roading switch manually to attempt a soft reset of the state crosscheck.

2. 2

   Access the Switch

   Locate the roading switch. Depending on your cab configuration, this will either be a rocker switch on the headliner/upper console or a master switch on the external guidance mechanical drive.

3. 3

   Test and Clean Connections

   Disconnect the wiring harness from the switch. Clean the terminals with contact cleaner. Test the switch for proper continuity when toggled.

4. 4

   Replace the Switch

   If the switch fails the continuity test or is physically damaged, replace it with a new OEM switch.

5. 5

   Harness Repair

   If the switch is functional, test the harness for continuity between the switch connector and the Steering Valve Controller pins. Repair any broken or shorted wires.

6. 6

   Controller Calibration/Replacement

   If the switch and wiring are perfectly functional, the fault lies within the Steering Valve Controller's internal logic or hardware. The controller may require a software re-flash (e.g., updating to SVC software version 2.02) or complete replacement by a certified CNH dealer.