CLAAS Id7821h / 7821h – Hydraulic Control Module (HYD) A060 / A60: Short-circuit to the 12V on the CLAAS vehicle CAN bus

The communication network (CAN bus) line is receiving unintended 12-volt power, which disrupts the digital communication between the tractor's control modules.

• Axion 810
• Axion 840
• Axion 850
• Axion 880
• Axion 920
• Axion 950
• Axion 960
• Arion 410
• Arion 430
• Arion 530
• Arion 550
• Arion 620
• Arion 640
• Arion 650
• Xerion 3300
• Xerion 3800

1. 1

   Check the CLAAS vehicle CAN bus network lines for physical damage.

2. 2

   Check the Hydraulic Module HYD (A060) for signs of water ingress or pin oxidation.

3. 3

   Check connectors and harness continuity linking the HYD module to the rest of the CAN bus.

4. 4

   Test the CAN High and CAN Low lines specifically for a short-circuit to a 12V power source.

5. 5

   Verify the fuses, main power supply (12V), and ground connections feeding the A060 module.

1. 1

   Document Codes

   Note all error codes present on the tractor. Analyze the interaction between them, as a CAN bus short (Id7821h) will often generate secondary communication errors (e.g., ECU not responding) in other modules.

2. 2

   Access the Module

   Locate the A060 HYD module (e.g., on Axion 800 series, it is typically located on the left side under the cab upholstery).

3. 3

   Visual Inspection

   Disconnect the module and inspect the connectors. Look for oxidized pins or water intrusion around the A060 controller.

4. 4

   Harness Testing

   Using a multimeter, measure the CAN bus pins on the harness side. Verify if the short to 12V is present in the wiring harness. If a wire is chafed and touching a 12V power line, repair the damaged section of the harness.

5. 5

   Module Testing

   Check the power and ground supply directly at the A060 connector. If the wiring harness is completely intact and tests perfectly, the internal circuitry of the A060 HYD module has likely failed and is bridging 12V to the CAN network.

6. 6

   Replace Component

   Replace the damaged harness section or the A060 HYD module as required.

7. 7

   Clear and Retest

   Use the CLAAS Diagnostic System (CDS) to clear all error codes. Test the tractor's hydraulic functions and drive it to ensure the anomaly does not reappear.