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U0664: Lost Communication With Rear HVAC Air Cutoff Actuator

What Does U0664 Mean?

U0664 is a diagnostic trouble code indicating: Lost Communication With Rear HVAC Air Cutoff Actuator. This code relates to the vehicle systems system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

What To Do Next

  1. 1
    Find your vehicle above

    Click your make and model for real owner reports and common causes specific to your vehicle.

  2. 2
    Check for recalls

    Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.

  3. 3
    Get a professional diagnosis

    A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.

Related Codes

U0659 Lost Communication With Left Front Temperature Actuator U0660 Lost Communication With Left Rear Temperature Actuator B U0661 Lost Communication With Right Rear Temperature Actuator A U0662 Lost Communication With Right Rear Temperature Actuator B U0663 Lost Communication With Rear Mode Actuator U0665 Lost Communication With Fuel Rail Pressure Sensor Bank 2 U0666 Lost Communication With Reductant Pressure Sensor U0667 Lost Communication With Engine Oil Temperature Sensor A