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U code network High severity

U0116 Lost Communication With Coolant Temperature Control Module

The OBD2 code U0116 indicates a loss of communication between the vehicle's control module and the coolant temperature control module, suggesting a potential issue with wiring, connectors, or the module itself

Definition

The OBD2 code U0116 indicates a loss of communication between the vehicle's control module and the coolant temperature control module, suggesting a potential issue with wiring, connectors, or the module itself

Common causes

  • Faulty coolant temperature control module
  • Damaged wiring or connectors
  • Poor electrical connections
  • Failed engine control module (ECM)
  • Blown fuse
  • Corroded terminals
  • Software issues or glitches
  • Short circuit in the wiring harness

Common misdiagnoses

  • Faulty Engine Control Module (ECM)
  • Wiring issues or shorts in the harness
  • Faulty coolant temperature sensor
  • Issues with the thermostat
  • Problems with the powertrain control module (PCM)
  • Faulty connectors or terminals
  • Malfunctioning transmission control module (TCM)
  • Battery or charging system issues

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other trouble codes that may be present. Sometimes, multiple codes can provide more context for the issue

  2. 2. Inspect the Wiring and Connectors

    Visual Inspection: Check the wiring harness and connectors related to the coolant temperature control module 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 pushed back

  4. 4. Test the Coolant Temperature Control Module

    If accessible, test the coolant temperature control module for proper operation. This may involve checking the module's power and ground connections

  5. 5. Use a multimeter to verify that the module is receiving the correct voltage

  6. 6. Check for Communication Issues

    Use a scan tool to check if the coolant temperature control module is communicating with the vehicle’s network. If it is not, there may be a communication issue

  7. 7. Inspect the CAN (Controller Area Network) bus for faults. This may involve checking other modules for communication errors

  8. 8. Inspect the Fuses

    Check the vehicle’s fuse box for any blown fuses that may affect the coolant temperature control module or related systems

  9. 9. Look for Ground Issues

    Ensure that the ground connections for the coolant temperature control module and related components are secure and free of corrosion

  10. 10. Perform a Network Test

    If you have access to advanced diagnostic tools, perform a network test to check for any issues with the vehicle’s communication network

  11. 11. Check for Software Updates

    Sometimes, manufacturers release software updates that can resolve communication issues. Check if there are any updates available for the vehicle’s ECU

  12. 12. Clear Codes and Test Drive

    After performing the above checks and repairs, clear the trouble codes and take the vehicle for a test drive to see if the code returns

  13. 13. Consult Technical Service Bulletins (TSBs)

    Look for any TSBs related to the U0116 code for your specific vehicle make and model. Manufacturers may have specific recommendations or known issues.1

  14. 14. Replace the Module (if necessary)

    If all other troubleshooting steps fail and the coolant temperature control module is confirmed to be faulty, consider replacing it.1

  15. 15. Seek Professional Help

    If you are unable to resolve the issue, it may be best to consult a professional mechanic or technician who has experience with your vehicle make and model. By following these steps, you should be able to identify the root cause of the U0116 code and take appropriate action to resolve the issue