Case IH 15279 - AST – AST (Advanced Steering Technology) module / Steering Valve Controller (SVC): Steering wheel sensor - speed crosscheck between the steering valve main and safety controllers failed

This code indicates a synchronization or data mismatch issue where the speed or position data interpreted by the main controller does not match the data interpreted by the safety redundant controller, causing the system to disable auto-guidance to prevent unintended steering movements.

• MAXXUM T4E
• VESTRUM CVX
• Magnum
• Steiger
• Puma
• Maxxum
• Vestrum
• Farmall
• Axial-Flow 7010
• Axial-Flow 7120
• Axial-Flow 7230
• Axial-Flow 8010
• Axial-Flow 8230
• Axial-Flow 9120
• Axial-Flow 9230

1. 1

   Inspect the CAN bus communication lines and wiring harness between the steering wheel sensor (SASA) and the steering valve controller for chafed wires, loose pins, or corrosion.

2. 2

   Verify that the steering wheel sensor is receiving proper operating voltage (typically 9-32 VDC) and has a solid ground.

3. 3

   Check for accompanying AST codes (such as 15280 through 15283) which indicate CAN communication failures rather than a mechanical sensor failure.

4. 4

   Ensure the steering wheel sensor is securely mounted to the steering column and is mechanically engaging without slipping.

5. 5

   Verify that the Steering Valve Controller (SVC) and Steering Redundant Controller (SRC) software versions are up to date (e.g., version 2.02 or newer).

1. 1

   Power Down

   Turn off the machine, remove the key, and disconnect the battery to ensure safety while working on the steering system.

2. 2

   Harness Repair

   If the diagnostic checks revealed damaged wiring or corroded connectors at the steering wheel sensor or the PVED-CLS valve controller, repair or replace the affected harness sections.

3. 3

   Sensor Replacement

   If the wiring is intact and CAN voltages are correct but the crosscheck still fails, the steering wheel sensor (SASA) is likely outputting erratic data. Remove the steering column covers, disconnect the sensor, and replace it with a new OEM unit.

4. 4

   Controller Replacement

   If a new sensor does not resolve the issue, the internal microprocessors in the steering valve controller (PVED-CLS) may have failed. The valve controller unit will need to be replaced.

5. 5

   Reassembly and Calibration

   Reconnect the battery and power on the machine. Clear the inactive fault codes and perform a steering system calibration (AST calibration) via the instrument cluster (H-menus) or the AFS Pro display to synchronize the new sensor/controller with the machine's straight-ahead position.