John Deere 959.09 – CCU: Incorrect CAN bus message, from VTV control unit.

Data transmission failure between the VTV (CommandCenter™ Display / Virtual Terminal) and the CCU (Chassis Control Unit). The CCU is not receiving expected CAN bus messages (such as time and date values) from the VTV, indicating a physical problem with the CAN bus wiring, a CAN bus overload, or a software/hardware failure.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6M Series Tractors
• 6105M
• 6115M
• 7R Series Tractors
• 7200R
• 7230R
• 7270R
• 8R / 8RT Series Tractors
• 8235R
• 8245R
• 8310R
• 8360R
• 9R / 9RT Series Tractors
• 9470RT
• 9520RT
• 9570RT
• Self-Propelled Sprayers

1. 1

   Check for accompanying codes indicating missing CAN messages across multiple modules, which could point to a broader CAN bus short or overload.

2. 2

   Inspect the CAN bus wiring harness and connectors between the CommandCenter™ display processor and the CCU for loose connections, pushed-back pins, corrosion, or rodent damage.

3. 3

   Verify CAN bus voltage using a multimeter on the CAN High and CAN Low lines (should be 1.5V to 2.5V). High or low voltage indicates a short to power or ground.

4. 4

   Check unswitched and switched power supplies, as well as the battery ground to the VTV, to ensure they are secure and providing adequate voltage.

5. 5

   Ensure that the software on both the CCU and the VTV are up to date and compatible.

1. 1

   Power Down

   Turn off the machine and disconnect the battery ground to prevent electrical shorts during inspection.

2. 2

   Harness Repair

   Disconnect the harness at the VTV and the CCU. Perform a continuity test on the CAN bus wires. If resistance is high or a wire is broken, repair or replace the damaged section of the wiring harness.

3. 3

   Clean Connections

   Apply electrical contact cleaner to the pins on both the CCU and VTV connectors. Reconnect the harnesses securely.

4. 4

   Re-test

   Reconnect the battery, power on the tractor, and clear the stored diagnostic codes. Operate the machine to see if the code returns.

5. 5

   Software Flash

   If the wiring is intact but the code returns, connect the John Deere Service ADVISOR tool and flash the latest software updates to both the CCU and the VTV.

6. 6

   Component Replacement

   If the display is unresponsive, or if the wiring and software are confirmed good but the CCU still cannot communicate with the VTV, the VTV processor is likely internally failed and must be replaced. In rarer cases, the CCU itself may be the faulty component.