AIC 521276.09 – LIN Bus 3 Fault. John Deere AIC System Alert.

AIC 521276.09 (AIC )

Code: 521276.09



This error code, AIC 521276.09, signals a fault within the LIN Bus 3 system, specifically relating to incorrect or absent messages from the LIN Bus Module at Positions K or P. This lack of data suggests a communication breakdown, which may be caused by issues within the LIN Bus itself or faults in the transmitting module. Such disruptions can significantly impact the transmission of operational data across the network.


The system has responded to this fault by limiting certain functionalities that depend on LIN Bus 3, in order to prevent erroneous operations and ensure the stability of the control system.


  • Inspect the LIN Bus 3 network, focusing on the modules at Positions K and P, for any physical damage, disconnections, or wear that could be disrupting communication.
  • Utilize diagnostic tools to test the LIN Bus 3’s signal integrity and functionality. Look for breaks or inconsistencies in the communication that could be causing the data transfer issues.
  • Review the configurations and settings of the affected LIN Bus modules to ensure they are correctly configured and capable of communicating effectively within the network.
  • Replace or repair any faulty modules or components that are found to be contributing to the problem. Ensure that all new or repaired parts are properly integrated into the system.
  • After repairs and adjustments, recalibrate the network and conduct extensive testing to verify that all system functionalities relying on LIN Bus 3 are restored and operating correctly.


Regular maintenance of LIN Bus networks is critical for ensuring reliable and efficient communication between various vehicle systems. Proactive troubleshooting and correction of network issues are essential to maintaining operational continuity and avoiding system-wide disruptions.