John Deere 001504.09 – RPT: CAN BUS Message Fault Rear Chassis (RPT)

A communication breakdown has been detected on the CAN bus between the Rear PTO Control Unit (RPT) and other control modules. The FMI .09 indicates an abnormal update rate, meaning messages from the RPT are missing, delayed, or arriving too quickly. This prevents the proper functioning of systems connected to the rear chassis through the CAN bus.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 9230
• 9330
• 9430
• 9530
• 9630

1. 1

   Power cycle the tractor to see if the code clears

2. 2

   Visually inspect wiring harnesses connected to the rear chassis controllers (especially the RPT unit) for chafing, corrosion, or rodent damage

3. 3

   Check all battery and chassis ground connections for clean, tight, and solid contact (specifically look for broken eyelets)

4. 4

   Measure CAN bus voltages (CAN Power: 12V, CAN Ground: 0V, CAN High: ~2.5V, CAN Low: ~2.5V) to check for shorts or opens

5. 5

   Test CAN bus terminating resistors by measuring resistance between CAN High and CAN Low (should be ~60 Ohms; 120 Ohms indicates a faulty or disconnected resistor)

1. 1

   Isolate the fault

   Unplug controllers from the CAN bus one at a time to see if normal communication is restored.

2. 2

   Repair wiring and connections

   If a bad ground, loose connection, or damaged wire is found, repair it. For example, strip damaged ground wires, crimp on a new eyelet terminal, and seal with heat shrink tubing.

3. 3

   Test RPT controller

   Disconnect the RPT controller and observe if other CAN bus errors related to its absence appear. If they do, it suggests the rest of the network is functioning correctly.

4. 4

   Replace RPT controller

   If the RPT controller is identified as the faulty component and wiring is sound, replace the unit. Verify the exact part number with a dealer based on the machine's serial number.