Case IH 15206 – Steering Valve Controller (SVC): Steering valve controller has detected the CAN bus offline.

This indicates that the electronic steering valve has stopped receiving messages on the CAN data link. Communication between the steering valve controller, the Tractor Control Unit (TCU), and other devices on the CAN bus has been interrupted.

• Steiger T4B
• Case IH Magnum Series
• Case IH Steiger Series
• Case IH Puma Series
• Case IH Farmall Series
• Case IH Vestrum CVX Series

1. 1

   Check battery voltage to ensure the steering valve controller is receiving proper voltage (related codes 15200 and 15201 indicate voltage issues that can knock the controller offline)

2. 2

   Inspect the cable harness connecting the steering valve controller to the main CAN bus for moisture in the plugs, corrosion, or physical damage

3. 3

   Test CAN bus terminators for the standard 60 ohms of resistance across the CAN High and CAN Low lines with the battery disconnected

4. 4

   Connect the Case IH Electronic Service Tool (EST) to see if the Steering Valve Controller is visible on the network

1. 1

   Disconnect Power

   Turn off the machine and disconnect the battery to prevent electrical spikes during testing.

2. 2

   Inspect and Clean Connectors

   Locate the Steering Valve Controller. Disconnect the main harness and inspect the pins for corrosion, pushed-back pins, or water ingress. Clean with contact cleaner and apply dielectric grease.

3. 3

   Verify CAN Bus Wiring

   Using a multimeter, trace the CAN High and CAN Low wires from the steering valve controller back to the nearest splice or the Tractor Control Unit (TCU). Repair any open or shorted wires.

4. 4

   Replace Faulty Terminators

   If the CAN bus terminating resistors fail the bench test (e.g., open circuit instead of 120 ohms per resistor), replace them.

5. 5

   Update Firmware

   If the wiring and terminators are intact, reconnect the battery and use the Case IH Electronic Service Tool (EST) to flash/update the display and steering controller firmware.

6. 6

   Replace the Controller

   If the controller remains offline and will not accept a firmware flash, the Steering Valve Controller itself has failed internally and must be replaced.

7. 7

   Recalibrate

   After replacing the controller, perform a steering angle and valve calibration using the EST or the in-cab AFS display.