WOMS
U code network Medium severity

U1690 U1690: "Module Communication Failure

The OBD2 code U1690 indicates a "Module Communication Failure," meaning there is a problem with communication between the vehicle's control modules, which may affect their ability to share data or function properly

Definition

The OBD2 code U1690 indicates a "Module Communication Failure," meaning there is a problem with communication between the vehicle's control modules, which may affect their ability to share data or function properly

Common causes

  • Faulty wiring or connectors
  • Failed or malfunctioning control module
  • Poor ground connections
  • Corroded or damaged pins in connectors
  • Communication network issues (e.g., CAN bus problems)
  • Software or firmware issues in modules
  • Intermittent electrical connections
  • Low battery voltage or power supply issues

Common misdiagnoses

  • Faulty wiring or connectors
  • Defective control module
  • Software issues or updates needed
  • Battery or power supply problems
  • Grounding issues
  • Intermittent communication issues
  • Other unrelated sensor failures

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 which module is having communication issues

  2. 2. Inspect Wiring and Connectors

  3. 3. Check the wiring harnesses and connectors associated with the affected modules. Look for signs of damage, corrosion, or loose connections

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

  5. 5. Verify Power Supply

    Ensure that the affected modules are receiving the proper voltage and ground. Use a multimeter to check the power supply to the modules

  6. 6. Check for Module Faults

  7. 7. If a specific module is indicated in conjunction with the U1690 code, consider testing or replacing that module

  8. 8. If multiple modules are affected, the issue may be more systemic

  9. 9. Inspect the CAN Bus

  10. 10. The Controller Area Network (CAN) bus is responsible for communication between modules. Check for shorts, opens, or other issues in the CAN bus wiring

  11. 11. Use an oscilloscope to monitor the CAN bus signals if you have access to one

  12. 12. Look for Software Issues

  13. 13. Ensure that all modules have the latest software updates. Sometimes, communication issues can be resolved with a software update

  14. 14. If a module has been recently replaced, ensure it has been properly configured and programmed

  15. 15. Perform a Hard Reset

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

  16. 16. Check for Interference

    Sometimes, aftermarket accessories or modifications can interfere with module communication. If any modifications have been made, consider removing them temporarily to see if the issue resolves

  17. 17. Consult Technical Service Bulletins (TSBs)

    Check for any TSBs related to the U1690 code for your specific vehicle make and model. Manufacturers may have specific recommendations or known issues

  18. 18. Professional Diagnosis

    If the issue persists after performing the above steps, it may be necessary to consult a professional technician or dealership for further diagnosis. They may have specialized tools and knowledge to pinpoint the problem. By following these steps, you should be able to identify and resolve the underlying issue causing the U1690 code