GMC 2011 Sierra Denali Owner's Manual page 349

2. Then go to the front of the
vehicle and locate the secondary
hood release. This is located
under the hood, near the center
of the grille.
3. Push the secondary hood
release to the right.
4. Lift the hood.
Before closing the hood, be sure
all the filler caps are on properly.
Then bring the hood from full
open to within 152 mm (6 inches)
from the closed position, pause,
then push the front center of the
hood with a swift, firm motion to
fully close the hood.
Vehicle Care 10-5