GMC Acadia 2011 Owner's Manual page 80

3-26 Seats and Restraints
3. Push the latch plate into the
buckle until it clicks.
4. Pull up on the latch plate to
make sure it is secure. If the belt
is not long enough, see Safety
Belt Extender on page 3 31.
Position the release button on
the buckle so that the safety belt
could be quickly unbuckled if
necessary.
5. If equipped with a shoulder belt
height adjuster, move it to the
height that is right for you.
See Shoulder Belt Height
Adjuster later in this section
for instructions on use and
important safety information.
6. To make the lap part tight, pull
up on the shoulder belt.
It may be necessary to pull
the stitching on the safety belt
through the latch plate to fully
tighten the lap belt on smaller
occupants.