Air Quality Sensor
For vehicles with an air quality sensor, the climate control system adjusts to limit some exhaust fumes from being pulled inside your vehicle.
Press the AUTO button on the climate control to activate the air quality sensor. The recirculation indicator light comes on when poor quality air is detected. The air quality sensor will not maintain recirculation for an extended period to prevent the air inside the vehicle from becoming too dry or stuffy.
Under certain conditions, the air
quality sensor will not activate,
such as during cold weather or
with extreme odors. Press 
to
activate recirculation.
The air quality sensor system does not protect against carbon monoxide (CO), which you cannot see or smell. See Engine Exhaust.
See also:
Reactivation for Subsequent
Owners
Push and follow the prompts to
speak to an Advisor as soon as
possible after acquiring the vehicle.
The Advisor will update vehicle
records and will explain the OnStar
service offers and opt ...
Automatic Entry Recall
If entry/exit recall is programmed
on in the vehicle personalization
menu, automatic entry recall occurs
when the ignition is turned on.
See Vehicle Personalization.
To stop recall movement,
...
PARK BRAKE SET
For vehicles with the electric parking
brake, this message displays when
the parking brake has been applied
to the set position. See the electric
parking brake information under
Parking Brak ...