GMC Yukon Denalid Owner's Manual page 21

Folding and Tumbling the Seat(s) from the
Third Row Seats
CAUTION:
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Using the third row seating position while
the second row is folded, or folded and
tumbled, could cause injury in a sudden
stop or crash. Be sure to return the seat
to the passenger seating position. Push
and pull on the seat to make sure it is
locked into place.
To fold and tumble the seat from the third rows, if
your vehicle has them, do the following:
1. Make sure that there is nothing under, in front
of, or on the seat.
Notice: Folding a rear seat with the safety
belts still fastened may cause damage to the
seat or the safety belts. Always unbuckle
the safety belts and return them to their normal
stowed position before folding a rear seat.
2. Lift the lever(s), located on the bottom rear of
the second row seat(s) on the inboard side, to
release the seatback. The seatback will fold
forward.
3. Lift the same lever again to release the rear
of the seat from the floor. The seat will
tumble forward automatically.
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