WOMS
U code network High severity

U0067 Vehicle Communication Bus E (+) Low

The OBD2 code U0067 indicates a communication issue where the Vehicle Communication Bus E (+) is experiencing a low voltage condition, which may affect data transmission between modules

Definition

The OBD2 code U0067 indicates a communication issue where the Vehicle Communication Bus E (+) is experiencing a low voltage condition, which may affect data transmission between modules

Common causes

  • Faulty wiring or connectors in the communication bus
  • Malfunctioning control modules
  • Short circuit in the communication lines
  • Open circuit in the communication lines
  • Poor ground connections
  • Corroded connectors
  • Interference from aftermarket devices
  • Software issues or bugs in the control modules

Common misdiagnoses

  • Faulty Engine Control Module (ECM)
  • Faulty Transmission Control Module (TCM)
  • Bad wiring or connectors in the communication bus
  • Faulty Body Control Module (BCM)
  • Defective sensors or actuators
  • Battery or charging system issues
  • Faulty diagnostic tools or software errors
  • Issues with other control modules on the CAN bus

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other trouble codes that may be present. Sometimes, multiple codes can provide more context for the issue

  2. 2. Inspect Wiring and Connectors

  3. 3. Visually inspect the wiring and connectors associated with the Vehicle Communication Bus E. Look for signs of damage, corrosion, or loose connections

  4. 4. Pay special attention to any connectors that may have been disturbed during repairs or maintenance

  5. 5. Check for Short Circuits

  6. 6. Use a multimeter to check for short circuits in the wiring. Measure the resistance between the communication wires and ground to ensure there are no shorts

  7. 7. Test the Modules

  8. 8. Identify the modules that communicate over Bus E. Common modules include the Engine Control Module (ECM), Transmission Control Module (TCM), and others

  9. 9. Check if the modules are functioning properly. You may need to perform a module reset or reprogramming if they are not responding

  10. 10. Inspect the CAN Bus

  11. 11. If your vehicle uses a Controller Area Network (CAN) bus, check the integrity of the bus. Look for any signs of damage or interference

  12. 12. Use a CAN bus analyzer if available to monitor the communication on the bus

  13. 13. Check Power and Ground

  14. 14. Ensure that the modules connected to Bus E are receiving proper power and ground. Use a multimeter to verify voltage levels at the connectors

  15. 15. Look for Interference

  16. 16. Check for any aftermarket devices or modifications that may be interfering with the communication bus. This includes alarms, stereo systems, or other electronic devices

  17. 17. Perform a Hard Reset

  18. 18. Disconnect the vehicle's battery for a few minutes to reset the modules. Reconnect the battery and see if the code returns

  19. 19. Consult Technical Service Bulletins (TSBs)

  20. 20. Check for any TSBs related to your vehicle make and model that may address known issues with the communication bus

  21. 21. Seek Professional Help

  22. 22. If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician who has experience with your specific vehicle make and model. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the U0067 code