GM Service Manual Online
For 1990-2009 cars only
  1. Inspect for a partially open recirculation door.
  2. Ensure that the recirculation door closes properly in all modes except the MAX air conditioning mode. Perform repairs as necessary.

  3. Inspect all of the side door seals for the following conditions. Repair or replace faulty seals as necessary.
  4. • Damaged seals
    • Missing seals