John Deere 520965.06 – OIC (Operator Interface Console): CAN BUS Terminating Resistor, CAN BUS Current Too High.

This error code is generated when the control software detects that the current on the CAN BUS is excessively high, indicating a short circuit to ground within the CAN BUS network or at the terminating resistor.

• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6090MC
• 6100MC
• 6110MC
• 6090RC
• 6100RC
• 6110RC

1. 1

   Turn off the machine and disconnect the negative battery terminal to prevent module damage during testing.

2. 2

   Locate the two 120-ohm terminating resistors on the CAN bus (typically one in the roof panel to the right of the operator, and the second behind the instrument panel on the right-hand side of the steering column).

3. 3

   Using a digital multimeter, measure the resistance between the CAN High and CAN Low pins at a diagnostic connector. A healthy CAN bus should read approximately 60 ohms.

4. 4

   If the reading is significantly lower or shows continuity to ground, disconnect the terminating resistors one at a time and test each individually to ensure it reads 120 ohms.

5. 5

   If the resistors test fine, visually inspect the CAN bus wiring harness between the OIC, the Cab Control Unit, and the terminating resistors for chafed insulation, pinched wires, or exposed copper touching the tractor's metal chassis.

1. 1

   Disconnect Power

   Ensure the machine is powered off and the battery is disconnected.

2. 2

   Access the Faulty Component

   Remove the necessary interior cab trim panels (roof panel or lower dash panel) to access the damaged wiring section or the faulty terminating resistor.

3. 3

   Repair Wiring (If Applicable)

   If a short to ground is found in the harness, cut out the damaged section of the wire. Solder in a new section of wire of the same gauge and seal it with heat-shrink tubing to prevent future moisture ingress and grounding.

4. 4

   Replace Terminating Resistor (If Applicable)

   If a terminating resistor is internally shorted or damaged, unplug it from the harness connector and plug in the OEM replacement.

5. 5

   Reassemble and Test

   Reinstall all interior panels. Reconnect the battery.

6. 6

   Clear Codes

   Turn the key to the ON position, access the OIC diagnostic menu on the monitor, and clear the stored 520965.06 fault code. Start the machine and verify the code does not return.