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U code network High severity

U2370 Control Module Communication Bus Off

The OBD2 code U2370 indicates a communication issue where a control module is unable to communicate over the vehicle's communication bus, often due to a fault in the module or wiring

Definition

The OBD2 code U2370 indicates a communication issue where a control module is unable to communicate over the vehicle's communication bus, often due to a fault in the module or wiring

Common causes

  • Faulty control module
  • Damaged wiring or connectors
  • Poor ground connections
  • Communication bus interference
  • Software issues or bugs
  • Low battery voltage
  • Faulty or disconnected sensors
  • Corroded terminals or connectors

Common misdiagnoses

  • Faulty control module
  • Wiring issues
  • Poor ground connections
  • Corrupted software/firmware
  • Faulty sensors
  • Battery or power supply problems
  • Communication network issues
  • Incorrectly installed aftermarket accessories

Troubleshooting steps

  1. 1. Check for Other Codes

    Start by scanning the vehicle for any other diagnostic trouble codes (DTCs). Other codes may provide additional context or indicate related issues

  2. 2. Inspect Wiring and Connectors

  3. 3. Visually inspect the wiring and connectors associated with the control modules on the communication bus. Look for signs of damage, corrosion, or loose connections

  4. 4. Pay special attention to the ground connections, as poor grounding can lead to communication issues

  5. 5. Check Power Supply

    Ensure that the control module in question is receiving the proper voltage and ground. Use a multimeter to check the power supply to the module

  6. 6. Test the Control Module

  7. 7. If possible, test the control module itself. This may involve using a scan tool to check for communication with the module or replacing it with a known good unit to see if the issue persists

  8. 8. Some modules may have self-diagnostic capabilities that can provide additional information

  9. 9. Inspect the Communication Bus

  10. 10. Check the integrity of the communication bus (CAN bus, LIN bus, etc.). Look for short circuits, open circuits, or any other issues that could disrupt communication

  11. 11. Use an oscilloscope or a specialized scan tool to monitor the bus signals for proper voltage levels and signal integrity

  12. 12. Check for Interference

    Ensure that there are no aftermarket devices or modifications that could be interfering with the communication bus. This includes things like alarm systems, stereo installations, or other electronic accessories

  13. 13. Clear Codes and Test Drive

    After performing inspections and repairs, clear the codes using a scan tool and take the vehicle for a test drive to see if the code reappears

  14. 14. 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 communication bus problems

  15. 15. Seek Professional Help

    If the issue persists after performing these steps, it may be necessary to consult a professional technician or a dealership with advanced diagnostic tools and expertise. By following these steps, you should be able to identify and resolve the underlying issue causing the U2370 code