CLAAS 770Bh – BDG (A103): Function 3 and 4 Unavailable

The machine's control system has lost communication with the specific button or switch assigned to functions 3 and 4. The BDG (A103) module logs this fault when it does not receive a signal from the button for a duration of five seconds, rendering the assigned functions unavailable. This indicates a communication breakdown between the physical button on the multifunction lever and the control module.

• Axion 810-850 Series
• Axion 510-640 Series
• Lexion

1. 1

   Verify that fault code Id770Bh is active or present in the fault memory of the CEBIS terminal

2. 2

   Identify the specific physical button or rocker switch assigned to functions 3 and 4 on the CMOTION multifunction lever

3. 3

   Check for other active CAN bus communication faults that could be triggering this specific error

4. 4

   Inspect the wiring harness and connectors between the multifunction control lever and the corresponding control modules for loose connections, corrosion, or physical damage

1. 1

   Power down machine

   Turn off the machine and disconnect the battery to ensure safety during electrical inspection.

2. 2

   Access control lever connections

   Gain access to the underside and connection points of the multifunction control lever located in the operator's armrest.

3. 3

   Inspect and clean connectors

   Disconnect the main electrical connector for the control lever. Inspect the pins and sockets for any signs of corrosion, dirt, or damage. Clean with a suitable electrical contact cleaner if necessary.

4. 4

   Test wiring continuity

   If the connection appears clean and secure, use a multimeter to check the continuity of the wiring for the specific button (checking for an open circuit or a short circuit to ground) using a pinout diagram.

5. 5

   Replace multifunction lever

   If the wiring and connections are confirmed to be good, the fault lies within the button mechanism itself. Because these buttons are integrated, replace the entire multifunction control lever as a single unit.

6. 6

   Re-assemble and test

   Reconnect all electrical connectors, re-power the machine, and clear all fault codes. Test the functionality of all buttons on the control lever to ensure the issue is resolved.