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U code network High severity

U1072 Communication Bus Off

The OBD2 code U1072 indicates a communication issue where the vehicle's control module is unable to communicate with another module due to a "bus off" condition, often related to a fault in the communication network

Definition

The OBD2 code U1072 indicates a communication issue where the vehicle's control module is unable to communicate with another module due to a "bus off" condition, often related to a fault in the communication network

Common causes

  • Faulty or damaged wiring in the communication bus
  • Malfunctioning control modules
  • Poor connections or corroded terminals
  • Short circuits in the communication lines
  • Open circuits in the communication lines
  • Electrical interference from other components
  • Software issues or bugs in the control modules
  • Low battery voltage or power supply issues

Common misdiagnoses

  • Faulty ABS module
  • Defective engine control module (ECM)
  • Bad wiring or connectors
  • Malfunctioning body control module (BCM)
  • Issues with the transmission control module (TCM)
  • Battery or charging system problems
  • Faulty sensors (e.g., wheel speed sensors)
  • Incorrectly diagnosed communication issues with other 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. This can provide more context about the issue

  2. 2. Inspect Wiring and Connectors

    Visually inspect the wiring and connectors related to the communication bus (CAN bus). Look for signs of damage, corrosion, or loose connections

  3. 3. Pay special attention to the connectors at the control modules involved in the communication

  4. 4. Test the Communication Bus

    Use a multimeter or an oscilloscope to check the voltage levels on the CAN bus wires. The typical voltage levels should be around 2.5V to 2.7V when the bus is idle

  5. 5. Check for short circuits or open circuits in the communication lines

  6. 6. Check Control Modules

    Identify the control modules that are part of the communication network. If one module is malfunctioning, it can cause communication issues

  7. 7. If possible, perform a functional test on the modules to ensure they are operating correctly

  8. 8. Inspect for Interference

    Look for any aftermarket devices or modifications that may interfere with the communication bus, such as alarms, remote starters, or other electronic devices

  9. 9. Clear Codes and Test Drive

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

  10. 10. Check for Software Updates

    Sometimes, manufacturers release software updates for control modules that can resolve communication issues. Check with the dealership for any available updates

  11. 11. Professional Diagnosis

    If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership with advanced diagnostic tools. By following these steps, you should be able to identify and resolve the underlying issue causing the U1072 code