GM Service Manual Online
For 1990-2009 cars only
  1. Loosen the sliding side door rear striker bolts.
  2. Slide the door towards the striker.
  3. Ensure that the lock fully engages the striker.
  4. Add or delete spacers behind the striker in order to accomplish this adjustment.

    Caution: Refer to Fastener Caution in the Preface section.

  5. Adjust the sliding side door rear striker bolts and tighten to 24 N·m (18 lb ft).