WOMS
U code network High severity

U1086 Lost Communication with Vehicle Control Module

The OBD2 code U1086 indicates a loss of communication with the vehicle control module, suggesting that the module is not responding or is unable to communicate with other modules in the vehicle's network

Definition

The OBD2 code U1086 indicates a loss of communication with the vehicle control module, suggesting that the module is not responding or is unable to communicate with other modules in the vehicle's network

Common causes

  • Faulty Vehicle Control Module (VCM)
  • Damaged wiring or connectors
  • Poor ground connections
  • Corroded terminals
  • Faulty communication network (CAN bus issues)
  • Malfunctioning sensors or modules
  • Software or firmware issues
  • Battery or power supply problems

Common misdiagnoses

  • Faulty wiring or connectors
  • Defective vehicle control module (VCM)
  • Issues with other control modules
  • Battery or power supply problems
  • Corrupted software or firmware
  • Faulty sensors or actuators
  • Grounding issues
  • Communication network problems (CAN bus issues)

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 more context about the issue

  2. 2. Inspect Wiring and Connectors

  3. 3. Visually inspect the wiring and connectors related to the Vehicle Control Module (VCM) and other modules in the communication network

  4. 4. Look for damaged, corroded, or loose connections that could interrupt communication

  5. 5. Check Power and Ground

  6. 6. Ensure that the VCM is receiving proper power and ground. Use a multimeter to check voltage at the module's power and ground pins

  7. 7. If there is no power or ground, trace the wiring back to the fuse box or battery

  8. 8. Test the Communication Network

  9. 9. Use a scan tool to check the communication status of other modules in the network. If other modules are also unresponsive, the issue may be with the communication bus (CAN bus)

  10. 10. Check for short circuits or open circuits in the CAN bus wiring

  11. 11. Inspect Fuses

  12. 12. Check the fuses related to the VCM and communication network. A blown fuse can interrupt communication

  13. 13. Perform a Hard Reset

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

  15. 15. Check for Software Updates

  16. 16. Some manufacturers release software updates for their control modules. Check if there are any updates available for the VCM or other related modules

  17. 17. Test the Vehicle Control Module

  18. 18. If all other steps do not resolve the issue, the VCM itself may be faulty. Testing or replacing the module may be necessary

  19. 19. Consult Technical Service Bulletins (TSBs)

  20. 20. Look for any TSBs related to the U1086 code for your specific vehicle make and model. Manufacturers may have specific recommendations for addressing this issue

  21. 21. Seek Professional Help

  22. 22. If you are unable to diagnose or fix the problem, consider taking the vehicle to a qualified mechanic or dealership for further diagnosis. By following these steps, you should be able to identify the cause of the U1086 code and take appropriate action to resolve the communication issue