RLC 520542.03 – Vehicle CAN Bus (500 kBd), Voltage Too High

RLC 520542.03 (RLC )

Code: 520542.03



This diagnostic trouble code is generated if the voltage of CAN+ is too high, indicating a short to 12V.


When this error is detected, the control software may experience limited or no functionality, affecting the performance or operation of specific electronic control systems within the equipment.


  • Inspect CAN Bus Wiring:
    • Check the wiring and connectors associated with the CAN bus for signs of short circuits to 12V. Look for damaged insulation or exposed wires. Repair or replace any compromised wiring.
  • Verify Voltage Levels:
    • Measure the voltage levels on the CAN bus to ensure they are within the specified range. Identify and correct any voltage anomalies.
  • Check for Electrical Interference:
    • Ensure there are no sources of electrical interference near the CAN bus network that could be causing high voltage issues.
  • Verify Termination Resistors:
    • Ensure that proper termination resistors are installed at both ends of the CAN bus network. Incorrect termination can lead to voltage issues.
  • Update Control Software:
    • Make sure the control software is updated to the latest version to address any potential issues with CAN bus voltage regulation.


High voltage on the CAN bus can damage the electronic control systems and disrupt communication. Regular inspection and maintenance of the CAN bus network are essential to prevent such issues. Prompt diagnosis and resolution of high voltage conditions are crucial to maintain system functionality.

Control Units: John Deere

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