Chevrolet 2009 Suburban Owner's Manual page 52

If the shoulder portion of a passenger belt with a
free-falling latch plate is pulled out all the way, the
child restraint locking feature may be engaged.
If this happens, let the belt go back all the way and
start again.
Engaging the child restraint locking feature in the
right front seating position may affect the passenger
sensing system. See Passenger Sensing System
on page 1-90 for more information.
If the belt stops before it reaches the buckle, for
lap-shoulder belts with cinching latch plates, tilt the
latch plate and keep pulling the safety belt until
it can be buckled.
1-46
3. Push the latch plate into the buckle until it clicks. If
you find that the latch plate will not go fully into the
buckle, see if you are using the correct buckle.
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 1-53.
Position the release button on the buckle so that
the safety belt could be quickly unbuckled if
necessary.