WOMS
U code network High severity

U014D Lost Communication with Body Control Module (BCM) - No Communication

The OBD2 code U014D indicates that there is a loss of communication between the vehicle's control module and the Body Control Module (BCM), meaning the two systems are unable to exchange data

Definition

The OBD2 code U014D indicates that there is a loss of communication between the vehicle's control module and the Body Control Module (BCM), meaning the two systems are unable to exchange data

Common causes

  • Faulty Body Control Module (BCM)
  • Damaged wiring or connectors
  • Corroded connectors
  • Blown fuse
  • Faulty communication network (CAN bus)
  • Low battery voltage
  • Intermittent electrical connections
  • Software issues or programming errors

Common misdiagnoses

  • Faulty Body Control Module (BCM)
  • Wiring issues or damaged connectors
  • Faulty Engine Control Module (ECM)
  • Issues with the Instrument Cluster
  • Faulty Powertrain Control Module (PCM)
  • Battery or charging system problems
  • Corrupted software or firmware in the BCM
  • Faulty fuses or relay issues
  • Grounding issues
  • Communication network problems (CAN bus issues)

Troubleshooting steps

  1. 1. Check for Other Codes

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

  2. 2. Inspect the 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, corroded, or pushed back

  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 if other modules in the vehicle are communicating. If other modules are also not communicating, the issue may be with the CAN bus wiring

  9. 9. Scope Testing

    If available, use an oscilloscope to check the CAN bus signals for proper voltage levels and signal integrity

  10. 10. Check for Short Circuits

    Inspect the wiring for any short circuits to ground or power that could affect communication

  11. 11. Battery and Charging System

    Ensure that the vehicle’s battery is in good condition and fully charged. A weak battery can cause communication issues

  12. 12. Reset the Codes

    Clear the trouble codes using the OBD-II scanner and see if the code returns after a test drive. This can help determine if the issue is intermittent

  13. 13. Consult Technical Service Bulletins (TSBs)

    Check for any TSBs related to the BCM or communication issues for your specific vehicle make and model. Manufacturers may have known fixes for common problems

  14. 14. Professional Diagnosis

    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.Conclusion Troubleshooting U014D can be complex, as it involves multiple systems and components. Following these steps systematically can help identify the root cause of the communication loss with the BCM