Case IH 15254 – Steering Valve Main Controller or Safety Controller: Roading switch voltage outside of a valid range at power up.

When the tractor's ignition is turned on, the electrical voltage signal returning from the Auto Guidance Roading Switch (also known as the Master Roading Switch) is falling outside the expected operational parameters (likely indicating an open circuit, a short to ground, or a short to power).

• Steiger T4B
• Steiger Series 335
• Steiger Series 385
• Steiger Series 435
• Steiger Series 485
• Steiger Series 535
• Steiger Series 620
• Magnum Series 220 AFS Connect
• Magnum MX Series
• Optum Series
• Farmall Series 40
• Farmall Series 45
• Farmall Series 50 (CVT)
• Farmall Series 75C
• Farmall Series 115U
• Puma Series
• Maxxum Series

1. 1

   Manually toggle the master roading switch on and off to see if the switch is stuck between states and clears the error

2. 2

   Check the ISOBus Diagnostic Page on the AFS Pro 1200 or Viper display to verify the live status of the roading switch

3. 3

   Inspect the wiring harness and connector (C656M) at the switch for loose pins, frayed wires, or corrosion

4. 4

   Use a multimeter to check the voltage at the switch terminals during power-up to confirm if the voltage is missing (open circuit) or shorted

1. 1

   Power Down

   Turn off the tractor and disconnect the battery ground to prevent electrical spikes.

2. 2

   Access the Switch

   Remove the trim panel on the headliner or upper console where the Auto Guidance Roading Switch is mounted.

3. 3

   Disconnect the Harness

   Unplug the wire connector from the back of the switch.

4. 4

   Inspect Terminals

   Check the female wire terminals inside the connector. If they are damaged or corroded, they will need to be re-pinned.

5. 5

   Remove and Replace

   Pop the faulty switch out of the bezel and snap the new OEM roading switch into place.

6. 6

   Reconnect and Reassemble

   Plug the harness back into the switch and reinstall the console trim.

7. 7

   Test the System

   Reconnect the battery and power up the tractor. Verify that fault code 15254 is no longer active. Engage the switch and check the steering settings page to ensure it displays "GPS – ISO" or the correct steering mode.