Case IH A-G-630 - Display – Instrumentation Module (INST2) or Vehicle Controller (CCM): No Communication with Steering Controller

The display message indicates a physical or network-level loss of CAN bus communication between the tractor's main computer/display and the autoguidance steering controller. This is most frequently caused by a severe voltage drop to the steering controller, a failed CAN-bus terminator, or a break in the wiring harness.

• MAGNUM AFS Connect
• STEIGER AFS Connect
• Steiger
• STX series (STX 280-535)
• Magnum
• Farmall

1. 1

   Check the alternator voltage on the tractor's display and verify that the steering controller is receiving a full 12+ volts (steering controllers are highly sensitive to low voltage).

2. 2

   Test the CAN-bus implement and vehicle voltages (normal operating voltage is typically around 2.4V on CAN-Low and CAN-High).

3. 3

   Disconnect and reconnect the main round plug at the steering controller to rule out a loose connection.

4. 4

   Clear old or inactive codes from the diagnostic menu, as some steering systems will lock out and refuse to communicate until cleared.

1. 1

   Clear Codes & Reboot

   Clear the fault codes through the diagnostic menu and restart the tractor. If the steering controller comes back online, it may have been a temporary software glitch.

2. 2

   Reroute Power Supply

   If the controller repeatedly drops offline, the standard repair is to bypass auxiliary power ports (do not run power from a cigarette lighter or shared cab plug). Run an independent, direct power supply wire with an inline fuse link straight from the battery to the steering controller to eliminate voltage drops.

3. 3

   Replace CAN Terminators

   If direct power does not restore communication, locate and replace the CAN-bus terminators on the network.

4. 4

   Test and Replace Harness

   Trace the wire harness running from the steering controller/sensors to the main vehicle controller. Check for continuity. Harnesses routed near moving parts (like the flywheel or pivot sensors) are prone to wear and may need to be replaced.