GMC 2010 Sierra - Manual (Page 93)

Some child restraints that have a top tether are
designed for use with or without the top tether being
attached. Others require the top tether always to be
attached. In Canada, the law requires that
forward-facing child restraints have a top tether, and
that the tether be attached. Be sure to read and follow
the instructions for your child restraint.
If the child restraint does not have a top tether, one can
be obtained, in kit form, for many child restraints. Ask
the child restraint manufacturer whether or not a kit is
available.
Lower Anchor and Top Tether Anchor
Locations
Regular Cab —
Two-Passenger
Front Seat
Regular Cab —
Three-Passenger
Front Seat
i (Top Tether Anchor):
Seating positions with top
tether anchors.
Do not install a child restraint in the center front seat
position. See Securing a Child Restraint in the Center
Front Seat Position on page 2‑61 for more information.
2-51