WOMS
U code network High severity

U029B Lost Communication With Drive Motor Control Module "C

The OBD2 code U029B indicates a loss of communication with the Drive Motor Control Module "C," suggesting that the vehicle's control module is not receiving or sending data properly to this specific module

Definition

The OBD2 code U029B indicates a loss of communication with the Drive Motor Control Module "C," suggesting that the vehicle's control module is not receiving or sending data properly to this specific module

Common causes

  • Faulty Drive Motor Control Module "C"
  • Wiring issues (damaged, corroded, or loose connections)
  • Faulty communication lines (CAN bus issues)
  • Power supply problems to the module
  • Software or firmware issues in the module
  • Other related module failures affecting communication
  • Grounding issues in the electrical system

Common misdiagnoses

  • Faulty Drive Motor Control Module
  • Wiring issues or damaged connectors
  • Faulty Battery or power supply issues
  • Malfunctioning Vehicle Control Module
  • Software or firmware issues
  • Faulty sensors related to the drive motor
  • Issues with the communication network (CAN bus)

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other related trouble codes. This can provide more context and help identify if there are other issues present

  2. 2. Inspect Wiring and Connectors

    Visual Inspection: Check the wiring harness and connectors related to the Drive Motor Control Module (DMC) for any signs of damage, corrosion, or loose connections

  3. 3. Connector Pins

    Ensure that the pins in the connectors are not bent, corroded, or damaged

  4. 4. Check Power and Ground

    Verify that the Drive Motor Control Module is receiving the correct voltage and ground. Use a multimeter to check for proper voltage at the module's power and ground terminals

  5. 5. Test the Drive Motor Control Module

    If possible, perform a functional test of the Drive Motor Control Module. This may involve using specialized diagnostic equipment or software to communicate with the module

  6. 6. If the module is suspected to be faulty, consider replacing it or testing it in another vehicle if available

  7. 7. Inspect the CAN Bus System

    Since U029B is a communication-related code, check the Controller Area Network (CAN) bus for issues. Look for

  8. 8. Open circuits

  9. 9. Short circuits

  10. 10. Faulty modules on the bus

  11. 11. Use a CAN bus scanner to monitor communication between modules

  12. 12. Check for Software Updates

    Sometimes, communication issues can be resolved with a software update. Check with the manufacturer for any available updates for the vehicle’s control modules

  13. 13. Clear Codes and Test Drive

    After performing the above checks and repairs, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code returns

  14. 14. Consult Technical Service Bulletins (TSBs)

    Look for any TSBs related to the specific make and model of the vehicle. Manufacturers may have issued guidance on common issues related to the U029B code

  15. 15. Seek Professional Help

    If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or technician who has experience with the specific vehicle and its systems.Conclusion Troubleshooting the U029B code involves a systematic approach to checking for communication issues, inspecting wiring and connections, and ensuring that all related components are functioning correctly. By following these steps, you can often identify and resolve the underlying problem