John Deere 1511 – Cornerpost: Missing Grain Loss CAN Message

The Cornerpost Control Unit (C03) has not received an expected CAN bus message from the Right Control Unit (E02/RCU) related to the grain loss monitoring system. This communication breakdown prevents the proper monitoring and control of grain loss during agricultural operations.

• 9540 WTS
• 9560 WTS
• 9580 WTS
• 9640 WTS
• 9660 WTS
• 9680 WTS
• 9560 STS
• 9660 STS
• 9760 STS
• 9860 STS
• CTS
• 9650 STS
• 9750 STS

1. 1

   Check for other active or stored Diagnostic Trouble Codes (DTCs), especially CAN bus codes ending in .09, power supply issues to the control units, or specific faults with the Right Control Unit (such as E02 639 09 3)

2. 2

   Inspect the wiring harness and connectors between the Cornerpost Control Unit and the Right Control Unit for chafing, corrosion, or loose connections

3. 3

   Verify the Right Control Unit is receiving a 12-volt supply and has a solid ground connection

4. 4

   Check CAN Bus voltages with the key on and network idle; CAN High and CAN Low should each measure approximately 2.5 volts

5. 5

   Use the onboard diagnostic mode through the cornerpost display to verify if CAN bus messages from the Right Control Unit (E02) are being received (display shows 1 if received, 0 if not)

1. 1

   Address other fault codes

   Diagnose and repair any other present fault codes first, as they may be the root cause of the communication issue.

2. 2

   Repair wiring and connectors

   Repair or replace any damaged wiring or connectors found during inspection. Clean, secure, and reseat connectors to resolve potential intermittent issues.

3. 3

   Power cycle the system

   Turn the key switch to the OFF position, wait at least 30 seconds for controllers to power down completely, and restart the machine to reset the controller.

4. 4

   Update software

   Use a John Deere service tool to check for and apply any available software updates for the control modules.

5. 5

   Isolate faulty controller

   Disconnect other controllers on the same CAN bus one at a time to determine if a different faulty module is disrupting the network.

6. 6

   Replace Right Control Unit

   If all diagnostics point to an internal failure, or if the controller cannot exit its boot block program, replace the Right Control Unit.