Case IH 519574-02 - UCM – UCM: Steering valve controller calibration fault

The steering valve controller has failed its calibration routine, the calibration checksum is invalid, or the wheel angle sensor data is out of range. This prevents the autoguidance (AFS AccuGuide) and advanced steering systems from engaging properly.

• MAGNUM AFS Connect
• Magnum AFS Connect (Models 180, 200, 220, 240, 250, 280, 310, 340, 380)
• Vestrum Series
• Steiger
• Optum
• Puma
• Flagship Axial-Flow Combines (e.g., 7250, 8250, 9250)
• Mid Range Common Cab Combines

1. 1

   Ensure the hydraulic oil is at normal operating temperature, as cold oil will cause the steering valve calibration to fail

2. 2

   Inspect the wheel angle sensor (steering angle sensor) in the articulation hinge or steering axle for wear, loose mounting hardware, or a damaged wiring harness

3. 3

   Check the LVDT (Linear Variable Differential Transformer) sensor connection directly on the hydraulic steering valve

4. 4

   For combines, measure the steering cylinder rod length to ensure it is within 1/4 inch on both sides when wheels are straight, adjusting tie rods if necessary

1. 1

   Position machine

   Move the machine to a wide-open, flat area.

2. 2

   Access calibration menu

   Navigate to the calibration menu on the display: CALIBRATION > CALIBR.

3. 3

   Perform Wheel Angle / Rear Wheel Position Calibration

   Drive the machine perfectly straight (engage manual guidance if helpful) and press 'OK' to save the center position.

4. 4

   Perform Steering Valve Calibration

   Select the steering valve calibration wizard. The system will perform one coarse calibration followed by three fine calibrations. Note: The machine will steer itself automatically during this test; keep clear of the steering cylinders.

5. 5

   Perform Roll Offset Calibration

   Navigate to CALIBRATION > NAV and calibrate the roll offset to ensure the navigation controller compensates for vehicle tilt.

6. 6

   Replace failed hardware

   If the calibration repeatedly fails (e.g., 'out of range after 4th attempt'), the electronic steering valve, the wheel angle sensor, or the UCM itself has suffered a hardware failure and must be replaced.