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 options available.
See also:
Reducing Speed While Using Cruise Control
If the cruise control system is already activated,
Press and hold the SET– button on the steering wheel until the desired
lower speed is reached, then release it.
To slow down in small amount ...
Resetting the Power Folding Mirrors
Reset the power folding mirrors if:
The mirrors are accidentally obstructed while folding.
They are accidentally manually folded/unfolded.
The mirrors will not stay in the unfolded position.
...
Vehicles Without a Navigation System
When the vehicle is on and the driver shifts into R (Reverse), the video
image automatically appears on the inside rearview mirror. Once the driver
shifts out of R (Reverse), the video image automat ...