WOMS
U code network Medium severity

U0059 Vehicle Communication Bus D (+) High

The OBD2 code U0059 indicates a communication issue where the Vehicle Communication Bus D (+) signal is detected as being high, which may suggest a fault in the communication network between various vehicle modules

Definition

The OBD2 code U0059 indicates a communication issue where the Vehicle Communication Bus D (+) signal is detected as being high, which may suggest a fault in the communication network between various vehicle modules

Common causes

  • Short circuit in the communication bus wiring
  • Faulty or damaged communication bus wiring
  • Malfunctioning control module
  • Poor ground connection
  • Corroded or damaged connectors
  • Interference from aftermarket devices
  • Faulty power supply to the control modules
  • Software issues or bugs in the control modules

Common misdiagnoses

  • Faulty ABS module
  • Faulty engine control module (ECM)
  • Faulty body control module (BCM)
  • Wiring issues or shorts in the communication bus
  • Faulty powertrain control module (PCM)
  • Defective sensors or actuators
  • Battery or charging system issues
  • Corroded connectors or terminals

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 communication bus. Look for signs of damage, corrosion, or loose connections

  4. 4. Pay special attention to the connectors for the modules that are part of the communication network

  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 lines and ground to ensure there are no unintended connections

  7. 7. Test the Modules

  8. 8. If you suspect a specific module is causing the issue, you can test it by disconnecting it and checking if the code persists. If the code goes away, the module may be faulty

  9. 9. Reconnect the module and check for proper operation

  10. 10. Inspect the Communication Bus

  11. 11. Use an oscilloscope or a specialized scan tool to monitor the communication bus signals. This can help identify if there are any irregularities in the data being transmitted

  12. 12. Check for Interference

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

  14. 14. Battery and Ground Connections

  15. 15. Check the vehicle’s battery and ground connections. A weak battery or poor ground can cause communication issues

  16. 16. Update Software/Firmware

  17. 17. In some cases, updating the software or firmware of the vehicle’s modules may resolve communication issues. Check with the manufacturer for any available updates

  18. 18. Clear Codes and Test Drive

  19. 19. After performing any repairs or adjustments, clear the trouble codes and take the vehicle for a test drive to see if the code returns

  20. 20. Consult a Professional

  21. 21. If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician who has experience with vehicle communication systems. By following these steps, you can systematically diagnose and potentially resolve the U0059 code. Always refer to the vehicle's service manual for specific information related to the make and model you are working on