Pontiac 2003 Montana Owner's Manual page 25

If the front legs are not attached correctly, the rear
legs will not attach to the rear set of floor pins.
If the front latches are not attaching correctly, check
that the seat is in the full rear position.
2. Make sure the bucket
seat is angled so that
the front hooks
clear the floor pins.
3. Firmly push the rear hooks onto the rear floor pins
by pushing down the rear of the seat.
4. Try to raise the seat to check that it is locked down.
5. Lift the seatback recliner lever or pull the nylon
strap on the back of the seat and raise the
seatback until it locks upright.
6. Push and pull on the seatback to make sure that it
is locked in place.
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