GMC 1997 Savana Van Owner's Manual page 74

To open the sliding door from inside, rotate the handle
upward and toward the rear of the vehicle. Then, slide
the door toward the rear of the vehicle to open.
To close the sliding door from inside, grasp the inside
handle and slide the door toward the front of the vehicle
to a closed position.
Make sure the door is completely closed before driving
your vehicle.
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