GM Service Manual Online
For 1990-2009 cars only

To wash your windshield, pull the lever with the wiper symbol on it toward you one time. When you release the lever, the washers will stop. The wipers continue wiping for about three cycles and will then either stop or return to your preset speed.

Caution: In freezing weather, do not use your washer until the windshield is warmed. Otherwise the washer fluid can form ice on the windshield, blocking your vision.