WOMS
U code network High severity

U0168 Lost Communication With Vehicle Security Control Module

The OBD2 code U0168 indicates a loss of communication with the Vehicle Security Control Module, suggesting that the vehicle's diagnostic system is unable to communicate with this specific module, which may affect...

Definition

The OBD2 code U0168 indicates a loss of communication with the Vehicle Security Control Module, suggesting that the vehicle's diagnostic system is unable to communicate with this specific module, which may affect security features

Common causes

  • Faulty Vehicle Security Control Module
  • Damaged wiring or connectors
  • Poor ground connections
  • Corroded terminals
  • Software issues or glitches
  • Faulty or disconnected CAN bus
  • Issues with the power supply to the module
  • Malfunctioning key fob or immobilizer system

Common misdiagnoses

  • Faulty Engine Control Module (ECM)
  • Faulty Body Control Module (BCM)
  • Wiring issues or shorts in the communication network
  • Faulty ignition switch
  • Battery or power supply issues
  • Faulty key fob or keyless entry system
  • Incorrectly programmed or malfunctioning security system
  • Faulty or damaged connectors or terminals

Troubleshooting steps

  1. 1. Check for Other Codes

    Use an OBD-II scanner to check for any additional trouble codes. Sometimes, other codes can provide context or indicate related issues

  2. 2. Inspect the Wiring and Connectors

    Visual Inspection: Check the wiring and connectors related to the Vehicle Security Control Module (VSCM) 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 the Vehicle Security Control Module

    Module Functionality: If possible, test the VSCM to ensure it is functioning correctly. This may require specialized diagnostic equipment

  5. 5. Power and Ground

    Verify that the VSCM is receiving proper power and ground. Use a multimeter to check voltage and continuity

  6. 6. Inspect the CAN Bus System

    CAN Bus Integrity: Since the VSCM communicates over the CAN bus, check the integrity of the CAN bus wiring. Look for shorts, opens, or high resistance in the wiring

  7. 7. Termination Resistors

    Ensure that the CAN bus has the correct termination resistors in place and that they are functioning properly

  8. 8. Check for Intermittent Issues

    Temperature and Vibration: Sometimes, issues can be intermittent due to temperature changes or vibrations. Monitor the vehicle for any patterns related to when the code appears

  9. 9. Perform a Hard Reset

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

  10. 10. Update Software/Firmware

    Check if there are any software updates available for the vehicle’s control modules. Sometimes, communication issues can be resolved with a software update

  11. 11. Consult Technical Service Bulletins (TSBs)

    Look for any TSBs related to the U0168 code or the VSCM for your specific vehicle make and model. Manufacturers may have known fixes or recommendations

  12. 12. Professional Diagnosis

    If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership. They may have access to advanced diagnostic tools and resources

  13. 13. Replace the Module (if necessary)

    If all other troubleshooting steps fail and the VSCM is determined to be faulty, replacement of the module may be necessary.Conclusion Always ensure that you follow safety precautions when working on a vehicle's electrical system. If you're not comfortable performing these steps, it's advisable to consult with a professional technician