GMC C-Series 2001 Owner's Manual page 84

Cruise Control (If Equipped)
With cruise control, you can maintain a speed of about
30 mph (48 km/h) or more without keeping your foot on
the accelerator. Cruise control does not work at speeds
below about 30 mph (48 km/h).
If you have an automatic transmission and you apply
your brakes, the cruise control will shut off.
2-40
If your vehicle has this
feature, it is located at
the end of the turn
signal/multifunction lever.
If you have a manual transmission and you apply your
brakes or push the clutch pedal, the cruise control will
shut off.
CAUTION:
D
Cruise control can be dangerous where you
can't drive safely at a steady speed. So,
don't use your cruise control on winding
roads or in heavy traffic.
D
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. Don't
use cruise control on slippery roads.