WOMS
U code network Medium severity

U0164 Lost Communication With HVAC Control Module

The OBD2 code U0164 indicates that there is a lost communication with the HVAC (Heating, Ventilation, and Air Conditioning) control module, meaning the vehicle's computer is unable to communicate with the HVAC system

Definition

The OBD2 code U0164 indicates that there is a lost communication with the HVAC (Heating, Ventilation, and Air Conditioning) control module, meaning the vehicle's computer is unable to communicate with the HVAC system

Common causes

  • Faulty HVAC control module
  • Damaged wiring or connectors
  • Poor ground connection
  • Blown fuse
  • Faulty communication network (CAN bus issues)
  • Corroded terminals
  • Software or firmware issues
  • Intermittent electrical connections

Common misdiagnoses

  • Faulty HVAC control module
  • Wiring issues or damaged connectors
  • Faulty body control module (BCM)
  • Power supply issues
  • Faulty climate control switches
  • Software or firmware issues
  • Faulty engine control module (ECM) or powertrain control module (PCM)

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 about the issue

  2. 2. Inspect the Wiring and Connectors

    Visual Inspection: Check the wiring harness and connectors related to the HVAC 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 or corroded

  4. 4. Check the HVAC Control Module

    Power and Ground: Verify that the HVAC control module is receiving power and ground. Use a multimeter to check the voltage at the module's power supply pins

  5. 5. Module Functionality

    If possible, test the HVAC control module in another vehicle or replace it with a known good unit to see if the problem persists

  6. 6. Inspect the CAN Bus System

    CAN Bus Communication: Since the HVAC control module communicates over the CAN bus, check for issues in the CAN bus wiring. Look for shorts, opens, or high resistance in the bus lines

  7. 7. Termination Resistors

    Ensure that the CAN bus has the proper termination resistors in place, as missing or faulty resistors can cause communication issues

  8. 8. Check for Interference from Other Modules

    Sometimes, other modules on the CAN bus can cause communication issues. Disconnect other modules one at a time to see if the problem resolves

  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 or Reprogram the Module

    If the HVAC control module is functioning but still showing the code, it may need a software update or reprogramming. Check with the manufacturer for any available updates

  11. 11. Consult Technical Service Bulletins (TSBs)

    Look for any TSBs related to the HVAC system or communication issues for your specific vehicle make and model. Manufacturers often release TSBs for known issues

  12. 12. Seek Professional Help

    If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or technician who has access to advanced diagnostic tools and equipment.Conclusion By following these troubleshooting steps, you can systematically identify and resolve the issue related to the U0164 code. Always ensure safety precautions are taken when working on a vehicle's electrical system