John Deere 002140.09 – PDU: CAN Bus Communication Failure: Cab Switch Module

The system has detected a communication breakdown on the CAN bus between the Cab Switch Module (CSM) and a primary control unit, such as the Primary Display Unit (PDU). The '.09' suffix indicates an abnormal update rate or communication loss, meaning expected data messages from the cab controls are missing. This disruption can lead to erratic behavior of machine functions controlled by cab switches and may cause the machine to stop and engage the park brake.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• S540
• S660
• S670
• S680
• S690
• 8335R
• 9360R
• 6M Series

1. 1

   Visually inspect the wiring harness and connectors between the Cab Switch Module and the main vehicle harness for corrosion, damage, abrasion, or loose connections

2. 2

   Verify that the Cab Switch Module is receiving the correct voltage and has a solid ground connection

3. 3

   Cycle the tractor's power off and on to perform a system reset and see if the code clears

4. 4

   Perform a CAN Bus Resistance Check: Disconnect the battery and measure resistance between CAN High and CAN Low (typically pins C and D at the diagnostic connector)

1. 1

   Perform diagnostic checks

   Perform all diagnostic checks listed above. Do not proceed with part replacement unless these checks have been completed.

2. 2

   Diagnose CAN bus resistance (Open Circuit)

   If the CAN bus resistance reads ~120 Ohms or open, locate and inspect the CAN bus terminating resistors for faults or disconnections. Trace the CAN harness for breaks or damage and repair as needed.

3. 3

   Diagnose CAN bus resistance (Short Circuit)

   If the resistance reads near 0 Ohms, inspect the harness for points where the CAN High and CAN Low wires may be shorted together and repair the wiring.

4. 4

   Inspect Cab Switch Module

   If the CAN bus resistance is correct (~60 Ohms) and the wiring appears undamaged, the fault likely lies with the Cab Switch Module (CSM) itself.

5. 5

   Replace Cab Switch Module

   Replace the faulty Cab Switch Module. After installation, cycle the power. Note that a new module may need to be programmed or configured by a dealer.