John Deere 1510 – Cornerpost Control Unit: Missing CAN Message from Right Control Unit

The Cornerpost Control Unit (C03) has stopped receiving expected CAN bus messages concerning combine temperatures from the Right Control Unit. This indicates a communication failure on the data link between these two controllers, rather than a direct fault with the temperature sensors themselves.

• 9540
• 9560
• 9580
• 9640
• 9660
• 9680
• 9560 STS
• 9660 STS
• 9760 STS
• 9860 STS
• S550
• S650
• S660
• S670
• S680
• S690

1. 1

   Visually inspect the wiring harness and connectors between the Cornerpost Control Unit and the Right Control Unit for damage, chafing, corrosion, or loose pins (pay special attention to the yellow and green twisted pair).

2. 2

   Perform a CAN Bus Resistance Check with power off and battery disconnected. Measure resistance between CAN High (yellow) and CAN Low (green) circuits; it should be approximately 60 Ohms. A reading of ~120 Ohms indicates a missing terminating resistor or open circuit, while near 0 Ohms suggests a short circuit.

3. 3

   Perform a CAN Bus Voltage Check with power on. Measure CAN High to ground (should be 2.5 to 3.0 volts) and CAN Low to ground (should be 2.0 to 2.5 volts). Deviations from these voltages can indicate a short to power or ground on one of the CAN lines.

1. 1

   Repair wiring and connectors

   If damage, corrosion, or loose connections were found during inspection, repair or replace the affected harness sections or pins. Clear fault codes and retest.

2. 2

   Correct CAN bus resistance

   If resistance is not ~60 Ohms, disconnect controllers one by one to isolate the faulty controller or harness section. Replace or reconnect any missing or faulty terminating resistors.

3. 3

   Isolate the faulty controller

   Disconnect the Right Control Unit connector. If CAN bus communication stabilizes on the rest of the network, the Right Control Unit is the source. Alternatively, test disconnecting the Cornerpost Control Unit (connector X500) to check for intermittent issues there.

4. 4

   Replace faulty control unit

   If diagnostics conclusively point to an internal failure, replace the Right Control Unit or the Cornerpost Control Unit as identified.