WOMS
U code network High severity

U0149 Lost Communication With Gateway "D

The OBD2 code U0149 indicates a loss of communication with the gateway module "D," which typically means that the vehicle's control modules are unable to communicate with each other due to a fault in the network or the...

Definition

The OBD2 code U0149 indicates a loss of communication with the gateway module "D," which typically means that the vehicle's control modules are unable to communicate with each other due to a fault in the network or the gateway module itself

Common causes

  • Faulty gateway module
  • Wiring issues or damaged connectors
  • Corroded terminals
  • Software or firmware issues
  • Low battery voltage
  • Faulty or disconnected sensors
  • Intermittent electrical connections
  • Aftermarket modifications or installations

Common misdiagnoses

  • Faulty Gateway Module
  • Wiring Issues
  • Corrupted Software
  • Faulty Body Control Module (BCM)
  • Faulty Engine Control Module (ECM)
  • Battery Voltage Issues
  • Faulty Instrument Cluster
  • Poor Ground Connections
  • Faulty Communication Lines
  • Other Module Failures

Troubleshooting steps

  1. 1. Check for Other Codes

    Use an OBD-II scanner to check for any additional trouble codes. Other codes may provide more context or indicate related issues

  2. 2. Inspect Wiring and Connectors

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

  4. 4. Pay special attention to the wiring harnesses that connect to the gateway module

  5. 5. Check the Gateway Module

  6. 6. Locate the gateway module (often referred to as the Body Control Module or similar) and ensure it is securely connected

  7. 7. If possible, test the module for proper operation or consider replacing it if it is suspected to be faulty

  8. 8. Inspect Fuses

  9. 9. Check the vehicle’s fuse box for any blown fuses that may affect the communication network. Replace any blown fuses and retest

  10. 10. Battery and Ground Connections

  11. 11. Ensure that the vehicle's battery is in good condition and fully charged. Weak batteries can cause communication issues

  12. 12. Check ground connections for corrosion or looseness, as poor grounding can lead to communication failures

  13. 13. Scan for Communication Issues

  14. 14. Use a professional-grade scan tool to check for communication between modules. This can help identify which module is not responding

  15. 15. Some scan tools can perform a network test to see if all modules are communicating properly

  16. 16. Check for Software Updates

  17. 17. Verify if there are any software updates available for the vehicle’s modules. Sometimes, manufacturers release updates to fix communication issues

  18. 18. Perform a Hard Reset

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

  20. 20. Inspect for Water Damage

  21. 21. Check for any signs of water intrusion in the area where the gateway module is located, as moisture can cause communication issues

  22. 22. Consult Technical Service Bulletins (TSBs)

  23. 23. Look for any TSBs related to the U0149 code for your specific vehicle make and model. Manufacturers may have specific recommendations or known fixes. 1

  24. 24. Professional Diagnosis

  25. 25. If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership. They may have specialized tools and knowledge to diagnose complex communication issues. By following these steps, you should be able to identify and potentially resolve the U0149 code. Always refer to the vehicle's service manual for specific procedures and specifications related to your vehicle