GMC SIERRA DENALI 2002 Manual page 58

With this system, use the LATCH system instead of the
vehicle's safety belts to secure a child restraint.
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CAUTION:
-
If a LATCH type child restraint isn't attached to
its anchorage points, the restraint won't be able
to protect a child sitting there. In a crash, the
child could be seriously injured or killed. Make
-
sure that a LATCH type child restraint is
properly installed using the anchorage points, or
use the vehicle's safety belts to secure the
restraint. See "Child Restraints" in the Index for
information on how to secure a child restraint in
your vehicle using the vehicle's safety belts.