Case IH 15256 – MTA CCM (Central Control Module) and Steering Valve Main / Safety Controllers: Incorrect steering valve controller configuration - Configured for incorrect steering valve type

The steering valve controller has detected a mismatch in its software configuration. The controller is programmed for a different type of steering valve than what is physically installed or expected by the network. (Note: The dossier also addresses code 15254, where the roading switch voltage is outside of a valid range at power up).

• Steiger T4B
• Steiger
• Magnum
• Puma
• Optum
• Farmall

1. 1

   Connect the CNH Electronic Service Tool (EST) to confirm whether the active code is 15256 (Configuration) or 15254/15253 (Roading Switch)

2. 2

   For code 15256: Check the current steering valve configuration in the EST software to see if it matches the physical valve installed on the tractor

3. 3

   For code 15254: Manually toggle the master roading switch between the 'Field' and 'Road' positions to see if the state changes on the diagnostic monitor

4. 4

   For code 15254: Test the roading switch with a multimeter to verify if the internal resistance is within specification or if the switch is stuck closed

5. 5

   For code 15254: Inspect the wiring harness and connectors between the roading switch and the steering controller for corrosion, backed-out pins, or chafing

6. 6

   For code 15254: Verify CAN communication between the steering controller and the vehicle controller

1. 1

   Connect Diagnostic Tool

   Plug the CNH EST into the machine's diagnostic port and turn the key to the ON position.

2. 2

   Address Configuration (If 15256 is active)

   Navigate to the steering controller configuration menu. Select the correct steering valve type that matches the tractor's build sheet. Save the configuration and cycle the key.

3. 3

   Address Roading Switch (If 15254 is active)

   Disconnect the harness from the back of the roading switch. Measure the voltage at the harness connector to ensure the controller is sending the correct reference voltage.

4. 4

   Replace Roading Switch

   If the voltage is correct but the switch resistance is out of range, remove the faulty roading switch from the console/headliner. Install a new OEM roading switch.

5. 5

   Inspect Wiring Harness

   If the switch tests good, trace the wiring harness back to the MTA CCM to locate and repair the short or open circuit.

6. 6

   Clear and Test

   Clear the inactive fault codes. Cycle the key power. Toggle the roading switch and verify that the AutoGuidance system can engage without the code returning.