John Deere 002003.09 – ICU: Transmission CAN Bus Communication Failure

A fault has been detected in the communication of the CAN BUS message within the Dash Module (FCC/ICU). The instrument cluster is failing to receive expected PTI or PTP messages from the transmission control unit over the CAN bus. This communication breakdown prevents the proper exchange of data between systems and can cause the tractor to fail to move, shut down abruptly, or exhibit erratic transmission behavior.

• 3033R
• 4044M
• 7000 Series
• 7630
• 7730
• 7830
• 7930
• 7720
• 7820
• 7920
• 7810
• 8000 Series
• 8130
• 8230
• 8330
• 8430
• 8530
• 6M Series
• 6R Series

1. 1

   Restart the tractor to determine if the fault code is intermittent or persistent

2. 2

   Check for other active CAN bus-related fault codes that might help isolate the issue

3. 3

   Inspect fuses F6 (IVT transmissions), F35 (PowrQuad Plus transmissions), and F24 (ECU communication)

4. 4

   Ensure battery terminals are clean and tight, and all ground connections are secure

5. 5

   Visually inspect the CAN bus wiring harness (twisted yellow and green wires) for cuts, abrasions, or rodent damage

6. 6

   Examine electrical connectors at the ICU, transmission controller, and under the operator's seat for corrosion, moisture, or pushed-out pins

7. 7

   Perform a CAN bus resistance check with the vehicle powered off (measure between CAN High and CAN Low; expected value is approximately 60 Ohms)

1. 1

   Rectify preliminary findings

   Replace any blown fuses, repair damaged wiring, and clean corroded connectors with electrical contact cleaner. Ensure all connections are secure.

2. 2

   Isolate harness faults

   If CAN bus resistance is 120 Ohms (indicating an open circuit/missing terminating resistor) or 0 Ohms (indicating a short circuit), use the split-half method. Disconnect modules one by one to observe resistance changes and isolate the faulty harness section or module.

3. 3

   Check for shorts to power or ground

   With the system powered off and a multimeter set to DC volts, verify there is no significant voltage between the CAN lines and chassis ground. Check for continuity between each CAN line and ground (there should be none).

4. 4

   Replace faulty control module

   If wiring and connections are sound, replace the suspected faulty transmission controller or ICU. Note that module replacement may require a software update or recalibration by a dealer.