John Deere 002049.09 – ICU / ACU / SFA: CAB Message Missing

A communication failure has been detected on the Controller Area Network (CAN bus) indicating an abnormal update rate. The logging control unit is not receiving expected messages from the Rear Chassis Module, also known as the Hitch Control Center (HCC). This indicates a potential issue with message transmission or reception within the system, which can range from a simple wiring or ground issue to a failed control unit.

• 6650
• 6750
• 6850
• 6950
• 7715
• 7815
• 7720
• 7820
• 7920
• 7630
• 7730
• 7830
• 7930
• 8130
• 8230
• 8330
• 8430
• 8530
• 9230
• 9330
• 9430
• 9530
• 9630
• 6145J
• 6165J
• 6180J
• 6205J
• 2254
• 2266

1. 1

   Restart the vehicle to see if the communication messages reset and clear the code

2. 2

   Check the fuse supplying power to the cab controller (typically F35 or F22 depending on the model) for a broken filament or lack of continuity using a multimeter

3. 3

   Visually inspect the wiring harness leading to and from the CAB controller for chafing, pinching, or heat damage

4. 4

   Inspect the main electrical connector for the CAB controller for corrosion, moisture, or pushed-out pins

1. 1

   Disconnect battery

   Before beginning any repair, disconnect the battery ground cable to prevent electrical shorts.

2. 2

   Replace blown fuse

   If fuse F35 or F22 is blown, replace it with a new fuse of the exact same amperage (e.g., 15A or 30A). Do not use a higher-rated fuse as it can cause severe electrical system damage.

3. 3

   Diagnose short circuit

   If the replacement fuse blows immediately or soon after installation, do not continue replacing it. Test the circuit to locate and repair the underlying short circuit in the wiring or the faulty component powered by that circuit.

4. 4

   Repair wiring

   If damaged wiring is found, repair it by soldering the broken wires and sealing the repair with heat-shrink tubing to protect against moisture and vibration.

5. 5

   Clean and reseat connectors

   If connectors are corroded, clean them thoroughly, apply dielectric grease to the seal to prevent future moisture intrusion, and ensure the connector is securely reseated.

6. 6

   Test system

   Reconnect the battery ground cable, start the vehicle, and verify if the fault code has cleared.

7. 7

   Consult dealer

   If the fault code persists after these repairs, the issue may be a faulty Cab Control Unit or a complex CAN bus problem requiring advanced dealer diagnostics.