CLAAS Id7704h / 7704h – BDG (A103): BDG module no longer transmits messages on Powertrain CAN bus

The BDG module (network communication module A103) is unable to transmit messages on the Powertrain CAN bus due to an excessive number of CAN frame errors. This indicates a communication disruption within the Powertrain CAN bus system, typically caused by physical layer issues such as incorrect termination resistance, wiring faults, electromagnetic interference, or a faulty CAN transceiver.

• Axion 800 Series
• Axion 810
• Axion 850
• Arion 500 Series
• Arion 510
• Arion 530
• Arion 550
• Arion 600 Series
• Arion 620
• Arion 640
• Arion 650

1. 1

   Check the Powertrain CAN bus network for short-circuits to ground, short-circuits to 12V, or open circuits.

2. 2

   Verify the sources of energy to the BDG module (A103), including all relevant fuses, power supply lines, and ground connections.

3. 3

   Inspect connectors and the continuity of wiring harnesses linking each component on the Powertrain CAN bus for bent, rusty, or damaged pins.

4. 4

   Verify that the Powertrain CAN bus shunts and terminating resistors are installed in the correct locations, as mixing them up is a known issue.

1. 1

   Visual & Physical Inspection

   Inspect the Powertrain CAN bus wiring harness for physical damage, rubbing, or corrosion, particularly at the BDG (A103) module connectors.

2. 2

   Electrical Testing

   Use a multimeter to test the CAN bus network resistance (typically 60 ohms across CAN High and CAN Low with the battery disconnected). Test the power supply and ground circuits to the BDG module.

3. 3

   Component Verification

   Ensure that the Powertrain CAN bus shunts and resistors are correctly installed. Resistors have an 'R' on their base, while shunts do not.

4. 4

   Module Replacement

   If the wiring, power, ground, and CAN bus integrity are all within specification, the BDG module (A103) itself may have an internal hardware failure and must be replaced.

5. 5

   Software/Calibration

   After replacing the component, check the compatibility of the program versions and settings. Perform any required module calibration or software flashing using the CLAAS Diagnostic System (CDS).