John Deere 002240.09 – RLC: CAN BUS Message Fault in RLC

A communication breakdown has occurred within the vehicle's electronic systems, specifically related to the Cab Roof Module (RLC). The RLC is experiencing issues with sending or receiving data on the Controller Area Network (CAN) bus, meaning messages are lost or corrupted. This can be caused by high network traffic (bus utilization) where controllers receive messages faster than they can process them, or by physical faults in the communication lines.

• Tractors
• Sprayers
• Combines
• Forage Harvesters

1. 1

   Cycle the key switch to see if the communication code clears

2. 2

   Reduce electrical load by turning off unnecessary accessories to see if high loads are interfering with module communication

3. 3

   Visually inspect the wiring harness connected to the Cab Roof Module for damage, corrosion, or loose connections (CAN bus wires are typically red for 12V, black for 0V, yellow for CAN High 2.5V, and green for CAN Low 2.5V)

4. 4

   With the battery disconnected, check the resistance between the CAN High and CAN Low pins (often pins C and D) at the diagnostic connector (approximately 60 ohms indicates intact terminating resistors; 120 ohms suggests a faulty or missing resistor)

5. 5

   Monitor the CAN bus state via the diagnostic interface for errors like 'Passive', 'Warn', or 'Bus Off', and check for high bus utilization (over 45%)

1. 1

   Address immediate errors

   Fix any simple issues found, such as replacing a blown fuse for a specific light controlled by the RLC.

2. 2

   Perform a cold boot

   Disconnect the unswitched power from the display or the relevant controller for an extended period (up to 24 hours) to resolve persistent software glitches.

3. 3

   Isolate the fault

   Unplug controllers from the CAN bus one at a time to see if the fault disappears, identifying if a single faulty controller is disrupting the entire network.

4. 4

   Repair or replace wiring

   If damaged wiring is found during inspection, repair the specific section or replace the entire Cab Roof Wiring Harness.

5. 5

   Replace the RLC module

   If all other troubleshooting steps fail and the fault is isolated to the Cab Roof Module, replace the unit.