Safety Belts: They're For Everyone - GMC 2001 Sierra 1500 Pickup Owner's Manual

To return the seat to the passenger position, lift the floor
load panels and latch them into the seatback. Lift the
seatback up and push rearward all the way. Then lower
the seat cushion until it latches into position.
Pull forward on the seatback and up on the seat cushion
to make sure the seat is securely in place.
Check to see that the buckles on the driver's side
seatback are accessible to the outboard and center
occupant and are not under the seat cushions.

Safety Belts: They're for Everyone

This part of the manual tells you how to use safety belts
properly. It also tells you some things you should not do
with safety belts.
And it explains the air bag system.
1-12
CAUTION:
Don't let anyone ride where he or she can't wear
a safety belt properly. If you are in a crash and
you're not wearing a safety belt, your injuries
can be much worse. You can hit things inside the
vehicle or be ejected from it. You can be seriously
injured or killed. In the same crash, you might
not be if you are buckled up. Always fasten your
safety belt, and check that your passengers' belts
are fastened properly too.