Here are the step by step instructions for locate the cabin air filter in your 2009 GMC Sierra 1500:
1. Open the glove box.
2. Squeeze the sides of the glove box and lower it down.
3. Locate the cabin air filter housing on the passenger side of the dash.
4. Remove the cabin air filter housing cover by pressing the release tab and pulling the cover off.
5. Remove the old cabin air filter from the housing.
6. Insert the new cabin air filter into the housing with the arrow pointing towards the passenger compartment.
7. Replace the cabin air filter housing cover and close the glove box.
Here is a video that shows you how to change the cabin air filter in a 2009 GMC Sierra:
[Video of cabin air filter replacement in a 2009 GMC Sierra](https://www.youtube.com/watch?v=o_o5x-2fQ4M)
