WOMS
U code network Medium severity

U1890 U1890: "Module Communication Failure

The OBD2 code U1890 indicates a "Module Communication Failure," meaning there is a problem with communication between the vehicle's control modules

Definition

The OBD2 code U1890 indicates a "Module Communication Failure," meaning there is a problem with communication between the vehicle's control modules

Common causes

  • Faulty wiring or connectors
  • Failed or malfunctioning control module
  • Poor ground connections
  • Intermittent communication issues
  • Corroded or damaged pins in connectors
  • Software or firmware issues
  • Low battery voltage or power supply problems
  • Electrical interference from other components

Common misdiagnoses

  • Faulty wiring or connectors
  • Defective control module
  • Software issues or updates needed
  • Power supply problems
  • Grounding issues
  • Intermittent communication issues
  • Other communication protocol failures

Troubleshooting steps

  1. 1. Check for Other Codes

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

  2. 2. Inspect Wiring and Connectors

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

  4. 4. Pay special attention to the wiring harnesses that connect the modules, as these can be prone to wear and tear

  5. 5. Check Power and Ground

  6. 6. Ensure that the affected module(s) are receiving proper power and ground. Use a multimeter to check voltage and ground continuity

  7. 7. If the module is not receiving power, trace the circuit back to the fuse box and check for blown fuses or damaged wiring

  8. 8. Test the Affected Module

  9. 9. If possible, test the affected module to see if it is functioning correctly. This may involve using specialized diagnostic tools or swapping the module with a known good one

  10. 10. If the module is faulty, it may need to be repaired or replaced

  11. 11. Check for Communication Issues

  12. 12. Use a scan tool to check if other modules in the network are communicating properly. If other modules are also showing communication errors, it may indicate a network issue

  13. 13. Look for issues with the CAN (Controller Area Network) bus, as this is often the communication protocol used between modules

  14. 14. Inspect the CAN Bus

  15. 15. Check the integrity of the CAN bus wiring. Look for shorts, opens, or high resistance in the bus lines

  16. 16. Use an oscilloscope to monitor the CAN bus signals if you have access to one. This can help identify communication problems

  17. 17. Reset the Modules

  18. 18. Sometimes, simply resetting the modules can resolve communication issues. Disconnect the battery for a few minutes, then reconnect it and see if the code returns

  19. 19. Software Updates

  20. 20. Check if there are any software updates available for the vehicle's control modules. Sometimes, manufacturers release updates to fix communication issues

  21. 21. Consult Technical Service Bulletins (TSBs)

  22. 22. Look for any TSBs related to the specific make and model of the vehicle. Manufacturers may have documented known issues and solutions for communication failures

  23. 23. Professional Diagnosis

  24. 24. If the issue persists after performing the above steps, it may be necessary to seek the help of a professional technician who has experience with the specific vehicle and access to advanced diagnostic tools. By following these steps, you should be able to identify and resolve the underlying cause of the U1890 code