CLAAS Id7709h / 7709h – BDG (A103): Message missing on the level of the front external control buttons.

Loss of CAN bus communication between the front external control buttons and the tractor's network, causing front external control functions to become unavailable.

• CLAAS Axion 800 Series
• CLAAS Axion 900 Series
• CLAAS Arion 500 / 600 Series

1. 1

   Check the CLAAS vehicle CAN bus network for overarching failures causing the missing message

2. 2

   Check the CAN network communication module BDG (A103) to verify it is communicating properly with other systems

3. 3

   Inspect connectors and the continuity of the harnesses linking the front external control buttons to the BDG module

4. 4

   Test the harness for any short-circuits (to 12V or ground) or open circuits

5. 5

   Verify the sources of energy (fuses, 12V supply, and ground) at the front external control button connector

6. 6

   Inspect the external buttons for physical damage, moisture ingress, or mechanical seizing

1. 1

   Document Codes

   Note all error codes present on the tractor to see if other CAN bus or BDG (A103) codes are active (such as Id7700h or Id7701h), which would indicate a wider network issue rather than just the buttons.

2. 2

   Visual Inspection

   Locate the front external control buttons on the front linkage/fender area. Inspect the switch housing and the wiring pigtail for physical damage, pulled wires, or water intrusion.

3. 3

   Electrical Testing

   Disconnect the front external control button harness. Using a multimeter, verify that the connector is receiving proper voltage and ground. Test the CAN High and CAN Low pins for continuity back to the BDG (A103) module.

4. 4

   Repair Wiring

   If an open circuit or short is found in the harness, repair the damaged wiring or replace the affected harness section.

5. 5

   Replace Component

   If the wiring, power, and ground are all within specification but the CAN message is still missing, the internal circuitry of the front external control button assembly has failed. Replace the button assembly.

6. 6

   Clear and Test

   Clear all error codes from the system. Test the front external controls to ensure the linkage operates correctly and the anomaly does not reappear.