GM Service Manual Online
For 1990-2009 cars only

Object Number: 419253  Size: SH

The aspirator valve is located on the upper left side of the HVAC case. The aspirator is connected to the in-car temperature sensor by a flexible hose assembly which contains a muffler to aid in noise reduction. Air movement within the HVAC case causes a vacuum at the aspirator valve which draws the air through the in car temperature sensor.