WOMS
U code network High severity

U0102 Lost Communication with Transfer Case Control Module

The OBD2 code U0102 indicates a loss of communication between the engine control module (ECM) and the transfer case control module, which may affect the operation of the vehicle's drivetrain

Definition

The OBD2 code U0102 indicates a loss of communication between the engine control module (ECM) and the transfer case control module, which may affect the operation of the vehicle's drivetrain

Common causes

  • Faulty Transfer Case Control Module
  • Damaged wiring or connectors
  • Poor electrical connections
  • Failed or malfunctioning vehicle control module
  • Corroded terminals
  • Blown fuses
  • Software issues or updates needed
  • Faulty CAN bus communication
  • Low battery voltage or power supply issues

Common misdiagnoses

  • Faulty Transfer Case Control Module
  • Wiring issues or damaged connectors
  • Faulty Engine Control Module (ECM)
  • Transmission Control Module (TCM) issues
  • Battery or charging system problems
  • Faulty sensors related to the transfer case
  • Software or programming issues
  • Grounding issues in the electrical system

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other related trouble codes. This can provide more context and help identify if there are other issues present

  2. 2. Inspect the Wiring and Connectors

    Visual Inspection: Check the wiring harness and connectors leading to the Transfer Case Control Module (TCCM) for any signs of damage, corrosion, or loose connections

  3. 3. Repair or Replace

    If you find any damaged wires or connectors, repair or replace them as necessary

  4. 4. Check Power and Ground

    Power Supply: Verify that the TCCM 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 TCCM is secure and functioning properly

  6. 6. Test the Transfer Case Control Module

    If the wiring and connections are intact, the TCCM itself may be faulty. You can test the module by

  7. 7. Checking for any visible damage

  8. 8. Using a scan tool to see if the module responds to commands

  9. 9. If possible, swap the TCCM with a known good unit to see if the problem persists

  10. 10. Check for Communication Issues

    CAN Bus Communication: Since the TCCM communicates over the CAN bus, check for issues in the network. Look for any other modules that may be having communication problems

  11. 11. Scan Tool Communication

    Use a scan tool to see if you can communicate with the TCCM. If you cannot, it may indicate a problem with the module or the communication lines

  12. 12. Inspect Related Components

    Check other components that may be related to the transfer case operation, such as the transmission control module (TCM) or any sensors that may affect the transfer case

  13. 13. Clear Codes and Test Drive

    After performing the above checks and repairs, clear the trouble codes using the scan tool 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 specific make and model of your vehicle. Manufacturers may have issued guidance on common issues related to the TCCM

  15. 15. Professional Diagnosis

    If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or dealership for further diagnosis. They may have specialized tools and knowledge to address more complex issues. By following these steps, you should be able to identify the root cause of the U0102 code and take appropriate action to resolve it