Case IH 15258 – Steering Controller and Vehicle Controller / TCU: Incorrect steering valve controller configuration

The steering valve main controller and safety controller are receiving a voltage or resistance reading from the roading switch circuit that falls outside the expected operating parameters, preventing the auto-guidance from engaging.

• Steiger T4B
• Case IH Steiger Series (335, 385, 435, 485, 535, 620)
• Case IH Magnum Series (e.g., Magnum 220)
• Case IH / New Holland machines with Pro 1200 displays and Nav II/III controllers

1. 1

   Manually toggle the master roading switch on and off to clear potential stuck contacts

2. 2

   Check ISOBUS / Display Status on the AFS Pro 1200 or guidance display for active roading switch error states or lockouts

3. 3

   Inspect the roading switch wiring harness (e.g., connector C656M on Steiger models) for loose pins, corrosion, or wire chafing

4. 4

   If code 15258 is present (incorrect configuration cause): Verify via the diagnostic menu that the steering valve controller is configured for the correct steering valve type

1. 1

   Power Down

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

2. 2

   Locate the Switch

   Locate the Roading Switch. Depending on the cab configuration, it is typically found on the upper headliner console or the right-hand armrest console.

3. 3

   Remove the Switch

   Carefully pry the switch bezel from the console panel and disconnect the wiring harness connector from the back of the switch.

4. 4

   Test the Circuit

   Using a multimeter, test the switch for continuity and proper resistance across its toggled states. If the switch shows open resistance when closed, or infinite resistance outside of the standard 12V/5V reference parameters, the switch has failed internally.

5. 5

   Inspect the Harness

   If the switch tests fine, use the multimeter to check the harness for continuity back to the steering controller to rule out a broken wire or a CAN communication harness failure.

6. 6

   Replace and Reassemble

   Plug the harness into the new OEM roading switch and snap it back into the console.

7. 7

   Clear Codes and Calibrate

   Reconnect the battery, power up the tractor, and toggle the roading switch to the 'Field' position. Verify that the fault code (15253/15254) clears and that the auto-guidance system is ready to engage.