GMC 2009 Sierra - Manual (Page 50)

Folding an empty rear seat with the safety belts
secured may cause damage to the safety belt or the
seat. When removing the child restraint, always
remember to return the safety belts to their normal,
stowed position before folding the rear seat.
1. Attach and tighten the lower attachments to the
lower anchors. If the child restraint does not have
lower attachments or the desired seating position
does not have lower anchors, secure the child
restraint with the top tether and the safety belts.
Refer to your child restraint manufacturer
instructions and the instructions in this manual.
1.1. Find the lower anchors for the desired
seating position.
1.2. Put the child restraint on the seat.
1.3. Attach and tighten the lower attachments on
the child restraint to the lower anchors.
2. If the child restraint manufacturer recommends that
the top tether be attached, attach and tighten the
top tether to the top tether anchor (loop), if
your vehicle has one. Refer to the child restraint
instructions and the following steps:
1-46