John Deere 2071.09 – XSC (Steering System Control Unit): CAN BUS Message Fault / CCU Message Missing

Indicates an abnormal update rate (FMI 09) where the XSC (Steering System Control Unit) is not receiving the required CAN bus messages (speed or status messages) from Source Address 71, which corresponds to the Central/Chassis Control Unit (CCU).

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6250R
• 7200R-7290R
• 8235R-8360R
• 9RX

1. 1

   Cycle power: Turn off the tractor, cycle the key switch, and restart the engine to see if the communication fault clears on the display.

2. 2

   Inspect communication lines: Check the CAN bus wiring harness between the XSC (Steering Module) and the CCU for physical damage, chafing, or interference.

3. 3

   Check connectors: Inspect the wiring connectors at both the XSC and CCU for corrosion, moisture, or loose pins.

4. 4

   Verify CCU operation: Ensure the Chassis Control Unit is powering up correctly by checking fuses and relays for lost power or ground.

5. 5

   Test sensor circuits: Use diagnostic tools to test the continuity of the CAN bus network and monitor voltage levels to ensure they are within the normal operating range.

1. 1

   Disconnect Power

   Always disconnect the battery before servicing sensitive electronic control units to prevent short circuits.

2. 2

   Repair Wiring

   If diagnostic checks reveal an open circuit, high resistance, or damaged wires in the CAN bus lines between the XSC and CCU, repair or replace the affected harness section.

3. 3

   Replace Faulty Module

   If the wiring is intact but the CCU is failing to broadcast, or the XSC has an internal failure preventing it from reading the bus, replace the faulty control unit.

4. 4

   Update Software

   After replacing a module, check for and install any available control software updates to address potential bugs or signal processing issues.

5. 5

   Calibrate Steering System

   If the XSC module is replaced, you must recalibrate the steering system, including the Wheel Angle Sensor and steering wheel sensors, using John Deere diagnostic software.