WOMS
U code network Medium severity

U1695 Lost Communication with Body Control Module

The OBD2 code U1695 indicates a loss of communication between the vehicle's control module and the body control module, suggesting a potential issue with wiring, connectors, or the module itself

Definition

The OBD2 code U1695 indicates a loss of communication between the vehicle's control module and the body control module, suggesting a potential issue with wiring, connectors, or the module itself

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 issues or programming errors
  • Other module failures affecting communication

Common misdiagnoses

  • Faulty Body Control Module (BCM)
  • Wiring issues or shorts in the communication lines
  • Defective or corroded connectors
  • Issues with the power supply to the BCM
  • Faulty Instrument Cluster
  • Malfunctioning Engine Control Module (ECM)
  • Problems with other control modules in the network
  • Software or firmware issues in the BCM or other modules

Troubleshooting steps

  1. 1. Check for Other Codes

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

  2. 2. Inspect the 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 module

  5. 5. Ground Connections

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

  6. 6. Inspect the Body Control Module

    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 the BCM is communicating with other modules on the CAN bus. If other modules are also not communicating, the issue may be with the bus itself

  9. 9. Scope Testing

    If available, use an oscilloscope to check the data lines for proper signal patterns

  10. 10. Check for Short Circuits

    Inspect the wiring for any short circuits that may be affecting communication. This can include shorts to power or ground

  11. 11. Look for Environmental Factors

    Consider if there have been any recent changes or repairs to the vehicle that could have affected the BCM or its wiring (e.g., bodywork, water leaks)

  12. 12. Reset the Codes

    After performing checks and repairs, clear the codes using the OBD-II scanner and see if the code returns after a test drive

  13. 13. Consult Technical Service Bulletins (TSBs)

    Check for any manufacturer-specific TSBs related to the U1695 code or BCM issues for your vehicle make and model

  14. 14. Seek Professional Help

    If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or automotive technician who has experience with your specific vehicle. By following these steps, you can systematically diagnose the cause of the U1695 code and take appropriate action to resolve the communication issue with the Body Control Module