Savaria Toyota Sienna Owner's Manual page 30

3. Slowly pivot the bench about the front anchorages until it stops.
The locking tether on the passenger side should automatically
engage when the bench is at 60 degrees (see "1" below). Check
that the bench is locked by attempting to pivot the bench back
down. If the tether is not locked, try firmly pressing the hinge
point until it makes contact with the frame (see "2" below). When
the locking tether is in this position, the bench should not fall
down until the locking tether is released.
Flipping the bench down (from the driver's side):
1. Release the locking tether by pulling the black strap (located at
the hinge point) in the rearward direction.
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