Case IH 15240 – Steering Valve Controller or Cab Control Module (CCM) / APH: Steering control message (from TCU) communication data error

CAN bus communication issue where the data packet sent from the Transmission Control Unit (TCU) regarding steering control is received as invalid, corrupted, or unreadable by the receiving module.

• Steiger T4B
• Farmall 40
• Farmall 45
• Farmall 50
• Farmall 115U Efficient Power
• Magnum 250
• Magnum 280
• Magnum 310
• Magnum 340
• Magnum 380
• Magnum Rowtrac
• Steiger
• Optum

1. 1

   Check for companion codes (such as 15241, 15242, and 15243) that can help isolate the communication issue

2. 2

   Verify controller configuration to ensure the 'Auxiliary steering device' is not incorrectly enabled in the system settings

3. 3

   Perform a CAN bus network test between the TCU and the steering controller (verify 60 ohms across the CAN High and CAN Low pins with the battery disconnected)

4. 4

   Inspect the wiring harness connecting the TCU to the steering valve controller for chafing, pinched wires, or corrosion at the connector pins

1. 1

   Reconfigure the Module

   Connect the Case IH Electronic Service Tool (EST). Navigate to the steering valve controller configuration and verify the settings. If the auxiliary steering device is enabled but not physically present on the machine, disable it and clear the code.

2. 2

   Repair Wiring

   If the configuration is correct, disconnect the harness at the TCU and the steering controller. Clean the connectors with electronic contact cleaner. If any CAN bus wires are damaged or show high resistance, repair or replace the affected harness section.

3. 3

   Update Software

   Ensure the TCU is running the latest software version (e.g., TCU software version 1.8.0.0 or newer, depending on the exact Magnum/Farmall model).

4. 4

   Replace the TCU

   If the wiring is intact, the configuration is correct, and the TCU is still broadcasting corrupted steering data (or is completely offline), the TCU itself has an internal fault and must be replaced.