WOMS
U code network Medium severity

U1485 U1485: Data Bus Communication Failure

The OBD2 code U1485: Data Bus Communication Failure indicates a problem with the communication between modules on the vehicle's data bus, which can affect the operation of various electronic systems

Definition

The OBD2 code U1485: Data Bus Communication Failure indicates a problem with the communication between modules on the vehicle's data bus, which can affect the operation of various electronic systems

Common causes

  • Faulty wiring or connectors in the data bus system
  • Malfunctioning control modules
  • Poor ground connections
  • Corroded or damaged terminals
  • Interference from aftermarket devices
  • Software issues or bugs in the control modules
  • Low battery voltage or weak battery
  • Faulty or damaged sensors on the data bus
  • Issues with the OBD-II port or connectors

Common misdiagnoses

  • Faulty ABS module
  • Defective engine control module (ECM)
  • Malfunctioning body control module (BCM)
  • Wiring issues or shorts in the data bus
  • Faulty sensors or actuators
  • Battery or charging system problems
  • Poor ground connections
  • Corrupted software or firmware in modules

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other trouble codes that may be present. Other codes can provide context and help identify the root cause of the communication failure

  2. 2. Inspect Wiring and Connectors

    Visually inspect the wiring and connectors associated with the data bus. Look for signs of damage, corrosion, or loose connections. Pay special attention to the connectors for the modules involved in the communication

  3. 3. Check for Short Circuits or Open Circuits

    Use a multimeter to check for continuity in the data bus wiring. Look for any short circuits or open circuits that could disrupt communication

  4. 4. Test the Modules

    Identify the modules that are part of the data bus communication. Test each module for proper operation. If a specific module is malfunctioning, it may need to be repaired or replaced

  5. 5. Inspect the Data Bus

    If applicable, check the data bus (CAN bus, LIN bus, etc.) for proper voltage levels and signal integrity. Use an oscilloscope if necessary to analyze the data signals

  6. 6. Check for Interference

    Look for any aftermarket devices or modifications that may interfere with the data bus communication. This includes things like alarm systems, stereo systems, or other electronic accessories

  7. 7. Reset the Codes

    After performing inspections and repairs, clear the trouble codes using the OBD-II scanner. Then, take the vehicle for a test drive to see if the code reappears

  8. 8. Consult Technical Service Bulletins (TSBs)

    Check for any TSBs related to the specific make and model of the vehicle. Manufacturers may have issued guidance on common issues related to data bus communication

  9. 9. Professional Diagnosis

    If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership. They may have specialized diagnostic tools and experience with the specific vehicle

  10. 10. Replace Faulty Components

    If a specific module or component is identified as faulty during testing, replace it as necessary. By following these troubleshooting steps, you can systematically identify and resolve the underlying issue causing the U1485 code