AIC 000639.12 (AIC 639.12) – Vehicle CAN Bus Fault

AIC 000639.12 (AIC 639.12)

Code: 000639.12

Shortcode: 639.12


The error code AIC 639.12 is triggered when the error threshold on the Armrest Interface Control Unit (AIC) for the vehicle’s CAN Bus has been exceeded. This situation could be caused by a short circuit, an open circuit, or excessive traffic on the CAN Bus, which disrupts normal communication and data flow.


To prevent further system complications and potential damage, the control unit has disabled the affected function until the issue can be resolved.


  • Conduct a thorough examination of the CAN Bus network for any signs of shorts or open circuits. Inspect the wiring and connectors for any physical damage or disconnections.
  • Utilize diagnostic tools to monitor traffic on the CAN Bus. Look for anomalies or spikes in data transmission that could indicate excessive traffic or signal conflicts.
  • Reduce the load on the CAN Bus if excessive traffic is detected. This may involve reconfiguring network settings or disconnecting non-critical devices temporarily to isolate the issue.
  • Check for and resolve any software or firmware issues within the AIC or connected devices that might be contributing to the fault. Update software and firmware to the latest versions as recommended by John Deere.
  • Once the necessary repairs and adjustments have been made, reset the AIC system and perform a series of tests to ensure that the CAN Bus is functioning correctly and that the restored functions are operating within normal parameters.


Maintaining a stable and efficient CAN Bus network is critical for the interconnected systems in modern machinery. Regular maintenance and proactive monitoring of the network can help prevent such faults and ensure reliable operation of all connected components.