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U code network High severity

U1950 Lost Communication with Body Control Module (BCM)

The OBD2 code U1950 indicates a loss of communication between the vehicle's control module and the Body Control Module (BCM), which may affect various electrical functions and systems in the vehicle

Definition

The OBD2 code U1950 indicates a loss of communication between the vehicle's control module and the Body Control Module (BCM), which may affect various electrical functions and 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 issues)
  • Blown fuses
  • Software or firmware issues in the BCM
  • Other module failures affecting communication

Common misdiagnoses

  • Faulty Body Control Module (BCM)
  • Wiring issues or damaged connectors
  • Faulty power supply or ground connections
  • Issues with other control modules
  • Faulty ignition switch
  • Software or firmware issues
  • Corrupted data in the vehicle's network
  • Faulty CAN bus communication lines

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other trouble codes that may be present. Codes related to other modules can provide context for the U1950 code

  2. 2. Inspect the Wiring and Connectors

    Visual Inspection: Check the wiring harness and connectors leading 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. Check for Communication Issues

    CAN Bus Communication: Use a scan tool to check if other modules are communicating properly. If other modules are also showing communication issues, the problem may be with the CAN bus wiring or a central issue affecting multiple modules

  9. 9. Network Integrity

    Inspect the CAN bus wiring for shorts, opens, or interference

  10. 10. Test the BCM

    If possible, test the BCM in another vehicle of the same make and model to determine if the module itself is faulty

  11. 11. Alternatively, you can try replacing the BCM with a known good unit to see if the issue resolves

  12. 12. Check for Software Updates

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

  13. 13. Clear Codes and Test Drive

    After performing the above checks and repairs, clear the 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 U1950 code or BCM issues for your specific vehicle make and model. Manufacturers may have specific recommendations or known fixes

  15. 15. Seek Professional Help

    If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or an automotive electrical specialist for further diagnosis. By following these steps, you should be able to identify the root cause of the U1950 code and take appropriate action to resolve the communication issue with the Body Control Module