WOMS
U code network Medium severity

U0249 Lost Communication With Entertainment Control Module Rear "B

The OBD2 code U0249 indicates a loss of communication with the rear entertainment control module "B," which may affect the functionality of rear entertainment features in the vehicle

Definition

The OBD2 code U0249 indicates a loss of communication with the rear entertainment control module "B," which may affect the functionality of rear entertainment features in the vehicle

Common causes

  • Faulty Entertainment Control Module
  • Wiring issues or damaged connectors
  • Corroded terminals
  • Software glitches or programming errors
  • Faulty communication network (CAN bus issues)
  • Low battery voltage or power supply issues
  • Intermittent connection or loose wiring
  • Malfunctioning related modules

Common misdiagnoses

  • Faulty Entertainment Control Module
  • Wiring issues or damaged connectors
  • Faulty Body Control Module (BCM)
  • Software glitches or outdated firmware
  • Battery or power supply issues
  • Faulty or corroded ground connections
  • Issues with the vehicle's CAN bus system
  • Faulty display or screen module

Troubleshooting steps

  1. 1. Check for Other Codes

    Use an OBD-II scanner to check for any additional trouble codes. Sometimes, multiple codes can provide more context for the issue

  2. 2. Inspect Wiring and Connectors

    Visual Inspection: Check the wiring harness and connectors related to the rear entertainment control module for any signs of damage, corrosion, or loose connections

  3. 3. Connector Pins

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

  4. 4. Check Power and Ground

    Power Supply: Verify that the entertainment control module is receiving the correct voltage. Use a multimeter to check the power supply at the module

  5. 5. Ground Connection

    Ensure that the ground connection is secure and free of corrosion

  6. 6. Test the Entertainment Control Module

    If possible, test the entertainment control module itself. This may involve swapping it with a known good module or using a diagnostic tool to check its functionality

  7. 7. Inspect the CAN Bus

    The communication between modules often occurs over the Controller Area Network (CAN) bus. Check for any issues with the CAN bus wiring, such as shorts or opens

  8. 8. Use a scan tool to monitor the CAN bus for any irregularities in communication

  9. 9. Check for Software Updates

    Sometimes, software glitches can cause communication issues. Check if there are any available updates for the vehicle’s software or firmware that may address the problem

  10. 10. Reset the System

    Clear the trouble codes using the OBD-II scanner and see if the code returns after a test drive. Sometimes, a reset can resolve temporary communication issues

  11. 11. 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 entertainment control module

  12. 12. Professional Diagnosis

    If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or dealership for a more in-depth diagnosis

  13. 13. Document Findings

    Keep a record of any findings, repairs made, and codes that were present. This information can be helpful for future reference or if professional assistance is needed. By following these steps, you should be able to identify the root cause of the U0249 code and take appropriate action to resolve the communication issue with the entertainment control module