GMC Envoy Owner's Manual page 147

S
(Resume/Accelerate): Move the switch to this
position to resume a set speed or to accelerate.
T
(Set): Press this button, located at the end of the
lever, to set a speed.
9 (Off): This position turns the cruise control system
off and cancels memory of a set speed.
With cruise control, you can maintain a speed of about
25 mph (40 km/h) or more without keeping your foot
on the accelerator. This can really help on long
trips. Cruise control does not work at speeds below
about 25 mph (40 km/h).
If you apply your brakes, the cruise control will shut off.
3-12
CAUTION:
{
Cruise control can be dangerous where you
cannot drive safely at a steady speed. So, do
not use your cruise control on winding roads
or in heavy traffic.
Cruise control can be dangerous on slippery
roads. On such roads, fast changes in tire
traction can cause needless wheel spinning,
and you could lose control. Do not use cruise
control on slippery roads.
CAUTION:
{
If you leave your cruise control on when you
are not using cruise, you might hit a button
and go into cruise when you do not want to.
You could be startled and even lose control.
Keep the cruise control switch off until you
want to use cruise control.