WOMS
U code network High severity

U014A Lost Communication with Body Control Module (BCM) - Invalid Data Received

The OBD2 code U014A indicates that there is a communication issue between the vehicle's control modules, specifically that the Body Control Module (BCM) is not responding or is sending invalid data

Definition

The OBD2 code U014A indicates that there is a communication issue between the vehicle's control modules, specifically that the Body Control Module (BCM) is not responding or is sending invalid data

Common causes

  • Faulty Body Control Module (BCM)
  • Damaged wiring or connectors
  • Corroded terminals
  • Poor ground connections
  • Faulty communication network (CAN bus)
  • Software issues or bugs in the BCM
  • Low battery voltage or power supply issues
  • Intermittent electrical connections
  • Other module failures affecting communication

Common misdiagnoses

  • Faulty Body Control Module (BCM)
  • Wiring issues or shorts in the communication lines
  • Faulty or corroded connectors
  • Issues with the power supply to the BCM
  • Problems with other control modules (e.g., PCM, TCM)
  • Software or firmware issues in the BCM
  • Faulty sensors sending incorrect data
  • Battery or charging system problems
  • Grounding issues in the electrical system
  • Intermittent communication faults due to environmental factors

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 about the issue

  2. 2. Inspect Wiring and Connectors

    Visual Inspection: Check the wiring harness and connectors related to the BCM 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 BCM is receiving the correct voltage. Use a multimeter to check the power supply to the BCM

  5. 5. Ground Connections

    Ensure that the ground connections for the BCM are secure and free of corrosion

  6. 6. Inspect the BCM

    Physical Condition: Check the BCM for any signs of physical damage or water intrusion

  7. 7. Reprogramming

    If the BCM has been replaced, ensure that it has been properly programmed to the vehicle

  8. 8. Test Communication Lines

    CAN Bus Communication: Use a scan tool to check the communication on the CAN bus. If other modules are not communicating, there may be a fault in the bus itself

  9. 9. Scope Testing

    If available, use an oscilloscope to check the signal integrity on the CAN lines

  10. 10. Check for Intermittent Issues

    Temperature Sensitivity: Sometimes, issues can be temperature-related. Monitor the vehicle to see if the problem occurs under specific conditions (e.g., after the vehicle warms up)

  11. 11. Vibration

    Check if the issue occurs when the vehicle is in motion or over bumps

  12. 12. Perform a Hard Reset

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

  13. 13. Update Software/Firmware

    Check if there are any software updates available for the BCM or other related modules. Sometimes, manufacturers release updates to fix communication issues

  14. 14. Replace the BCM

    If all other steps fail and the BCM is determined to be faulty, consider replacing it. Ensure proper programming and configuration after replacement

  15. 15. Consult Technical Service Bulletins (TSBs)

    Look for any TSBs related to the specific make and model of the vehicle. Manufacturers may have documented common issues and solutions.1

  16. 16. Seek Professional Help

    If you are unable to resolve the issue, consider consulting a professional mechanic or an automotive technician with experience in electrical systems and BCM diagnostics. By following these steps, you should be able to identify the root cause of the U014A code and take appropriate action to resolve the communication issue with the Body Control Module