ACU 002049.09 (ACU 2049.09 ) – CAB Communication Breakdown

ACU 002049.09 (ACU 2049.09)

Code: 002049.09

Shortcode: 2049.09


The error code ACU 2049.09 signals a failure in the armrest control unit to receive necessary messages from the CAB (Controlled Area Network Bus). This missing communication can affect various cabin-controlled operations and settings.


Due to this communication failure, the control unit automatically defaults the system to neutral, preventing any potentially unsafe movements or operations while the error persists.


  • Check the connectivity and integrity of the network cables and connectors between the CAB and the armrest control unit to ensure there are no physical damages or loose connections.
  • Utilize diagnostic tools to trace and verify the continuity of the CAN bus lines and to detect any disruptions or noise that could be interfering with signal clarity.
  • Reset the CAB system and the armrest control unit to clear any transient faults and restore default settings.
  • If these measures do not resolve the communication issue, it may be necessary to conduct a deeper investigation into the electrical system, possibly involving a replacement of segments of the wiring harness or connectors.
  • Consult with a certified John Deere technician who can provide advanced diagnostics and corrective actions if standard troubleshooting does not correct the issue.


Communication between the armrest control unit and CAB is essential for safe and efficient machine operation. Continuous monitoring and preventive maintenance of the communication system are recommended to avoid such disruptions.