WOMS
U code network Medium severity

U0197 Lost Communication With Telephone Control Module

The OBD2 code U0197 indicates a loss of communication with the Telephone Control Module, which may affect features related to hands-free calling and other telematics functions in the vehicle

Definition

The OBD2 code U0197 indicates a loss of communication with the Telephone Control Module, which may affect features related to hands-free calling and other telematics functions in the vehicle

Common causes

  • Faulty Telephone Control Module (TCM)
  • Wiring issues or damaged connectors
  • Corroded terminals
  • Faulty communication network (CAN bus issues)
  • Software glitches or programming errors
  • Low battery voltage or power supply issues
  • Interference from aftermarket devices or modifications

Common misdiagnoses

  • Faulty wiring or connectors
  • Defective Body Control Module (BCM)
  • Malfunctioning Infotainment system
  • Issues with the Instrument Cluster
  • Problems with the Powertrain Control Module (PCM)
  • Software glitches or updates needed
  • Battery or power supply issues
  • Faulty Telephone Control Module (TCM) itself

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 for the issue

  2. 2. Inspect Wiring and Connectors

    Visual Inspection: Check the wiring harness and connectors related to the Telephone Control Module (TCM) 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 TCM is receiving the correct voltage. Use a multimeter to check the power supply to the module

  5. 5. Ground Connection

    Ensure that the ground connection for the TCM is secure and functioning properly

  6. 6. Inspect the Telephone Control Module

    Module Condition: If accessible, inspect the TCM for any physical damage or signs of water intrusion

  7. 7. Re-seat the Module

    Disconnect and reconnect the TCM to ensure a good connection

  8. 8. Check for Communication Issues

    CAN Bus Communication: Since the TCM communicates over the CAN bus, check for issues with the CAN network. Look for other modules that may not be communicating properly

  9. 9. Scan Other Modules

    Use a scanner to check if other modules are reporting communication issues, which could indicate a broader network problem

  10. 10. Perform a Hard Reset

    Disconnect the vehicle's battery for a few minutes to reset the vehicle's electronic systems. Reconnect and see if the code reappears

  11. 11. Software Updates

    Check if there are any software updates available for the vehicle’s modules. Sometimes, manufacturers release updates to fix communication issues

  12. 12. Consult Technical Service Bulletins (TSBs)

    Look for any TSBs related to the TCM or communication issues for your specific vehicle make and model. Manufacturers may have specific fixes for known issues

  13. 13. Replace the Telephone Control Module

    If all other steps fail and the TCM is determined to be faulty, consider replacing the module. Ensure that the replacement part is compatible with your vehicle

  14. 14. Professional Diagnosis

    If you are unable to resolve the issue, it may be best to consult a professional mechanic or dealership. They have specialized tools and knowledge to diagnose complex communication issues.Conclusion By following these troubleshooting steps, you can systematically identify and address the cause of the U0197 code. Always ensure safety precautions are taken when working with vehicle electronics