GM Service Manual Online
For 1990-2009 cars only

Drain Hose Routing

A drain trough encircles the sunroof glass panel and water is drained off by the drain hoses located at each corner of the housing. A drain channel spans across the sunroof module at the rear of the glass panel and directs water into the trough.

  1. Ensure the front drain hoses are routed down the windshield pillars and out the center of the pillar between the door hinges. Ensure the hoses are not kinked. Replace any torn or cracked hose. Refer to Sunroof Housing Front Drain Hose Replacement or to Sunroof Housing Rear Drain Hose Replacement .
  2. Ensure the rear drain hoses are routed through the rear pillars and out of the rocker panel. Ensure the rear hoses are correctly routed in the metal roof slot and taped in place. Replace any torn or cracked hose. Refer to Sunroof Housing Front Drain Hose Replacement or to Sunroof Housing Rear Drain Hose Replacement .

Plugged Drain Hose

If a waterleak has occurred check for a plugged drain hose at each corner of drainage system.

  1. Open the sunroof window.
  2. To test for blockage, pour a small container of water into the module housing drain trough. Check each corner to confirm the drain hose is draining water.
  3. Use compressed air, 241 kpa (35 psi) or less to blow out any drain hose that is plugged.
  4. Test the system again.
  5. If the hose remains plugged, check to see it is correctly routed and does not have a kink. See Drain Hose Routing.
  6. Remove any hoses that remains plugged. For front hoses refer to Sunroof Housing Front Drain Hose Replacement or to Sunroof Housing Rear Drain Hose Replacement .
  7. Remove the blockage using the following steps.
  8. 7.1. Push mechanics wire through the hose to remove the obstruction.
    7.2. Use compressed air in order to blow out any remaining material.
    7.3. Reinstall the hose. Refer to Drain Hose Routing.

Disconnected Drain Hose

Inspect the drainage system for disconnected drain hoses. Complete the following steps in order to obtain partial access to drain hoses and check for a disconnected hose.

  1. Open the sunroof glass panel.
  2. Withdraw the headliner from around the sunroof module.
  3. Remove the power sunroof switch. Refer to Sunroof Switch Replacement .
  4. Remove the headliner as needed. Refer to Headlining Trim Panel Replacement in Interior Trim.
  5. Connect any disconnected hoses.
  6. Make certain that the rear drain hoses are correctly routed in the metal roof slot and taped in place.