Case IH 15232 - AST – AST (Advanced Steering) Controller: Steering wheel sensor - communication data error

The control module is failing to receive valid CAN bus communication data (or is receiving corrupted data) from the steering wheel angle/position sensor.

• MAXXUM T4E
• VESTRUM CVX
• Maxxum
• Puma
• Optum
• Farmall
• Steiger
• AFX8010
• 7010
• 7120
• 7230
• 8010
• 8120
• 8230
• 9010
• 9120
• 9230

1. 1

   Inspect the wiring harness and connector at the steering wheel sensor for corrosion, backed-out pins, or physical damage.

2. 2

   Verify the sensor is receiving proper operating voltage (9 - 32 VDC) and ensure the ground circuit is intact.

3. 3

   Test the CAN High and CAN Low communication lines between the steering wheel sensor and the AST controller for continuity, and check for shorts to ground or power.

4. 4

   Check the diagnostic display for other active CAN bus codes (such as 15233 or 15234). If multiple modules are dropping offline, the issue is likely in the CAN bus backbone rather than the sensor itself.

1. 1

   Power Down

   Turn off the machine and disconnect the battery to prevent electrical shorts during the repair.

2. 2

   Access the Sensor

   Remove the plastic shrouds/covers around the steering column to access the steering wheel sensor assembly.

3. 3

   Removal

   Disconnect the electrical harness connector from the sensor. Unbolt the sensor from its mounting position on the steering column (some models may require pulling the steering wheel depending on the exact column configuration).

4. 4

   Installation

   Install the new OEM steering wheel sensor and secure the mounting hardware.

5. 5

   Reconnect

   Plug the electrical harness back into the sensor, reassemble the steering column covers, and reconnect the battery.

6. 6

   AST Steering Calibration

   Using the Case IH Electronic Service Tool (EST) or the tractor's H-Menu/Pro 700 display, initiate the steering calibration procedure so the AST controller can learn the new sensor's 0-index (center) point and end-stop limits.

7. 7

   Clear Codes

   Clear the 15232 fault code from the AST module and test drive the machine to verify auto-guidance functionality.