John Deere 520425.07 – CCU, AIC, RLC, TEC, OIC: Received CAN Bus Messages, High Error Rate

Triggered when a control unit's error counter for the Controller Area Network (CAN) bus reaches an unusually high level, indicating persistent communication failures. This is typically a physical layer issue caused by electrical noise/interference, faulty wiring, corroded connectors, missing/failed termination resistors, or a malfunctioning module crashing the network.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 8225R
• 8245R
• 8270R
• 8295R
• 8320R
• 8335R
• 8345R
• 8370R
• 8400R
• 9470RT
• 9520RT
• 9570RT
• 210K
• 210L EP
• 310K
• 370E
• 410E
• 460E

1. 1

   Verify CAN Bus Resistance: With the machine off and battery disconnected, measure resistance across CAN-High and CAN-Low pins (Pins C and D). A healthy bus reads exactly 60 ohms. 120 ohms indicates a missing/failed resistor; lower indicates a short.

2. 2

   Inspect Physical Wiring and Connectors: Perform a visual inspection of the CAN bus harness for physical damage, loose connections, chafed wires, or verdigris (green corrosion)/moisture intrusion in Deutsch connectors.

3. 3

   Check Power and Grounds: Test for voltage instability such as weak batteries, voltage drops during cranking, or poor chassis grounds.

4. 4

   Isolate the Network: If the bus is overloaded, disconnect modules one by one while monitoring the network with diagnostic software or a scope to identify a malfunctioning device.

1. 1

   Disconnect power

   Turn the key switch OFF and disconnect the negative battery cable before servicing the electrical system.

2. 2

   Repair wiring and connectors

   If corrosion or wire damage was found during diagnostics, clean the connector pins thoroughly or splice in a new Deutsch connector pigtail. Ensure all pins are seated tightly.

3. 3

   Replace termination resistors

   If the backbone resistance was out of specification (not 60 ohms), locate the CAN bus terminators (usually at the extreme ends of the harness or integrated into a module) and replace any faulty passive terminators.

4. 4

   Address faulty nodes

   If a specific module was found to be flooding the network with errors, replace the module or update its control software to the latest version to resolve message processing conflicts.

5. 5

   Clear and test

   Reconnect the battery. Use John Deere diagnostic software to reset the CAN bus error counter. Perform an operational checkout (Key ON/Engine OFF, then Key ON/Engine ON) and monitor the CAN bus traffic to ensure the error rate remains low.