John Deere 520426.07 – CSM, AIC, OIC, or CCU: Vehicle CAN Bus Error Counter High

The error counter for the vehicle's Controller Area Network (CAN) Bus reaches an unusually high level, indicating an excessive error rate with received or transmitted CAN bus messages due to a persistent communication problem.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 8225R
• 8245R
• 8270R
• 8295R
• 8320R
• 8335R
• 8345R
• 8370R
• 8400R
• 9470RT
• 9520RT
• 9570RT
• 210K EP Tractor Loader
• 210L EP Tractor Loader
• 310K Backhoe Loader

1. 1

   Inspect the CAN bus wiring harness for physical damage, chafing, loose connections, or corrosion at the connectors.

2. 2

   Verify CAN bus termination resistors are installed at both ends of the network and test them with a multimeter (should read approximately 60 ohms across CAN High and CAN Low with the battery disconnected).

3. 3

   Check for electrical interference from aftermarket accessories or damaged components introducing noise into the CAN network.

4. 4

   Monitor CAN bus load using John Deere Service ADVISOR (or equivalent diagnostic software) to identify if a specific module is flooding the network with corrupted data.

1. 1

   Isolate the Fault

   If the network is crashing, unplug modules one by one (starting with the CSM or AIC, depending on which logged the code) while monitoring the CAN bus error counter via your diagnostic tool.

2. 2

   Repair Wiring

   If the error counter drops when a specific harness section is bypassed, repair or replace the compromised wiring and secure all pins in the connectors.

3. 3

   Replace Faulty Components

   If unplugging a specific module (e.g., the Cab Switch Module) restores network health and stops the error counter from climbing, that module has an internal CAN transceiver failure and must be replaced.

4. 4

   Replace Terminators

   If the termination resistance is out of spec (e.g., 120 ohms instead of 60 ohms, indicating one resistor has failed), replace the faulty CAN terminator.

5. 5

   Clear and Retest

   Reconnect all components, update the control software to the latest version, clear the stored 520426.07 code, and operate the machine to ensure the error counter remains low and normal function is restored.