CLAAS Id77CBh / 77CBh (11) – HYD (A60): CAN Bus Communication Error: Instruction Message from Valve 3 Missing or Improbable

The fault code indicates a CAN bus communication error where the 'Instruction' message from valve 3 is either not received or is deemed improbable. As a safety response, the system forces electrodistributor 3 to return to the neutral position.

• Axion 800 series
• Axion 810
• Axion 820
• Axion 830
• Axion 840
• Axion 850
• Arion 400 series
• Arion 500 series
• Arion 600 series

1. 1

   Check the integrity of the Hydraulic CAN bus network

2. 2

   Check the connectors and continuity of the wiring harnesses linking the HYD (A60) module and the A105-3 electrodistributor for short-circuits or open circuits

3. 3

   Check the sources of energy, including fuses, power supply voltage, and ground connections to the modules

4. 4

   Verify the operating conditions of the valve (e.g., hydraulic pressure, temperature, and check for mechanical seizing)

5. 5

   Check the compatibility of the program versions, settings, and calibration of the hydraulic module

1. 1

   Document Codes

   Note all error codes present on the tractor and analyze their interaction, as CAN bus errors can cascade and generate secondary codes.

2. 2

   Inspect Wiring

   Physically inspect the wiring harness running to electrodistributor 3 (A105-3) for chafing, corrosion, or pin damage at the connector.

3. 3

   Test Communication

   Use a multimeter or oscilloscope to verify CAN High and CAN Low signals at the valve connector.

4. 4

   Test Power/Ground

   Ensure the electrodistributor is receiving proper 12V supply and has a clean ground.

5. 5

   Replace Component

   If the wiring, power, and CAN network are intact but the 'Instruction' message is still missing/improbable, the internal electronics of the electrodistributor module (A105-3) have likely failed and the valve must be replaced.

6. 6

   Clear and Retest

   Clear all error codes from the HYD (A60) module, restart the tractor, and operate hydraulic valve 3 to confirm the anomaly does not reappear.