Setting Cruise Control
If the cruise button is on when not in use, it could get bumped and go into cruise when not desired. Keep the cruise control switch off when cruise is not being used.
The cruise control light on the instrument panel cluster comes on after the cruise control has been set to the desired speed.
1. Press the 
button.
2. Get up to the desired speed.
3. Press the −SET button and release it.
4. Take your foot off the accelerator.
See also:
Control Buttons
The buttons used to control the radio are:
RADIO/BAND: Press to turn the radio on and choose between AM, FM, and XM™,
if equipped.
MENU/SELECT: Press and turn to navigate the available menus.
...
Additional Factors Affecting System Operation
Safety belts help keep the
passenger in position on the seat
during vehicle maneuvers and
braking, which helps the passenger
sensing system maintain the
passenger airbag status.
See “Safety ...
Warranty
OnStar equipment may be
warranted as part of the new-vehicle
limited warranty. The manufacturer
of the vehicle furnishes detailed
warranty information. ...