John Deere 000639.08 – XSC / SSU / XMA: Vehicle CAN BUS Fault Steering Module (XSC)

A communication problem has been detected on the vehicle's Controller Area Network (CAN bus) related to the steering system. The Steering Module (XSC) has detected an issue in transmitting or receiving messages on the CAN bus, which could lead to slow steering response or system malfunction. This indicates a general communication breakdown within the system rather than a specific component failure.

• 8R Series
• 8245R
• 8400R
• 7R Series
• 9R Series
• 6M Series
• 6R Series

1. 1

   Cycle power by turning the machine off and restarting it to see if the transient communication fault clears

2. 2

   Check for other active fault codes in the system that could pinpoint the root cause of the communication error

3. 3

   Visually inspect the CAN bus wiring harness (CAN Power, CAN Ground, CAN High, and CAN Low) and connectors for damage, corrosion, or loose connections

4. 4

   Inspect fuses related to the steering control unit and other electronic modules

5. 5

   Check CAN bus voltages using proper tools (CAN High and CAN Low should both be approximately 2.5V when functioning correctly)

6. 6

   Check the CAN bus terminating resistors at each end of the network (faulty or missing resistors cause communication issues)

1. 1

   Address other fault codes

   If other fault codes are present, diagnose and repair those issues first, as they may be the root cause of the CAN bus fault.

2. 2

   Repair wiring and connectors

   If any damaged wiring or corroded connectors are found during inspection, repair or replace them. Ensure all connections are clean and secure.

3. 3

   Replace blown fuses

   If any blown fuses are found, replace them with new ones of the correct amperage. If the fuse blows again, diagnose and repair the underlying short circuit.

4. 4

   Replace faulty network components

   If diagnostic tests point to a specific faulty component, such as a sensor or another control unit on the CAN bus, replace that component.

5. 5

   Replace the Steering Controller

   If all other diagnostic steps fail to resolve the issue, verify the controller's power, ground, and network connections. If verified good, replace the Steering Controller (XSC/SSU/XMA).