Automatic Operation
The system automatically controls the fan speed, air delivery, air conditioning, and recirculation to heat or cool the vehicle to the selected temperature.
When the AUTO indicator light is on, the system is in full automatic operation.
To place the system in automatic mode:
1. Press AUTO.
2. Set the temperature. Allow the system time to stabilize. Then adjust the temperature as needed.
To improve fuel efficiency and to cool the vehicle faster, recirculation may
be automatically selected in warm weather. The recirculation light will not come
on. Press the 
to select recirculation;
press it again to select outside air.
See also:
Customer Assistance Offices (U.S. and Canada)
GMC encourages customers to call the toll-free number for assistance.
However, if a customer wishes to write or e-mail GMC, the letter should be addressed to:
United States
GMC Customer Assistance ...
Accessories and Modifications
Adding non-dealer accessories or making modifications to the vehicle can affect
vehicle performance and safety, including such things as airbags, braking, stability,
ride and handling, emissions s ...
Fuses and Circuit Breakers
The wiring circuits in your vehicle are protected from short circuits by a combination of fuses, circuit breakers and fusible thermal links.
This greatly reduces the chance of fires caused by electri ...