WOMS
U code network High severity

U013C Lost Communication with Body Control Module (BCM) A

The OBD2 code U013C indicates that there is a loss of communication with the Body Control Module (BCM) A, which may affect various electrical systems in the vehicle

Definition

The OBD2 code U013C indicates that there is a loss of communication with the Body Control Module (BCM) A, which may affect various electrical systems in the vehicle

Common causes

  • Faulty Body Control Module (BCM)
  • Damaged wiring or connectors
  • Corroded terminals
  • Poor ground connection
  • Faulty communication network (CAN bus)
  • Blown fuses
  • Software issues or programming errors
  • Intermittent electrical connections

Common misdiagnoses

  • Faulty Body Control Module (BCM)
  • Wiring issues or damaged connectors
  • Faulty Instrument Cluster
  • Faulty Engine Control Module (ECM)
  • Battery or charging system problems
  • Faulty fuses
  • Communication network issues (CAN bus problems)
  • Grounding issues
  • Faulty sensors or actuators
  • Software or programming issues

Troubleshooting steps

  1. 1. Check for Additional Codes

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

  2. 2. Inspect Wiring and Connectors

    Visual Inspection: Check the wiring harness and connectors related to the Body Control Module (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 damaged

  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 and configured for 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 communication lines

  10. 10. Check for Short Circuits

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

  11. 11. Look for Environmental Factors

    Consider if there have been any recent changes to the vehicle, such as aftermarket installations, that could affect the BCM or its communication

  12. 12. Perform a Hard Reset

    Disconnect the vehicle's battery for a few minutes to reset the BCM and clear any temporary communication issues

  13. 13. Consult Technical Service Bulletins (TSBs)

    Check for any TSBs related to the specific make and model of the vehicle that may address known issues with the BCM or communication problems

  14. 14. Replace the BCM (if necessary)

    If all other troubleshooting steps fail and the BCM is determined to be faulty, consider replacing it. Ensure proper programming and configuration after replacement.1

  15. 15. Seek Professional Help

    If you are unable to resolve the issue, it may be best to consult a professional mechanic or dealership with experience in diagnosing and repairing BCM-related issues. By following these steps, you should be able to identify the root cause of the U013C code and take appropriate action to resolve the communication issue with the Body Control Module