One or more heater & AC (HVAC) temperature and/or air delivery mode door actuator may fail, resulting in improper temperature or air delivery. If this occurs, fault code(s) should be stored in the HVAC control module which should assist in diagnoses.
Improper HVAC Temperature and/or Air Delivery Due to Failed Mode Door Actuator on GMC Sierra 1500 HD
Average mileage: 115,000 (115,000–115,000)
5 people reported this problem
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It only comes out in the defrost mode
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