The cabin air filter is located behind the glove box on the passenger side, inside a rectangular housing. Accessing it requires lowering the glove box and removing the filter cover to replace the filter.
Location and access
In most 2009 Sierra models with a cabin air filter, the unit sits just behind the passenger-side glove box. The glove box typically has small stops on each side; you collapse them by squeezing the sides to drop the box down, giving you access to the rectangular filter housing mounted on the far side.
What you’ll need
Gather these items before you begin the replacement process.
- Replacement cabin air filter compatible with your vehicle (check your VIN or parts catalog for the exact part number).
- Flat-head screwdriver or trim removal tool (optional) to release clips.
- Flashlight to inspect the housing and orientation.
With the right parts on hand, you can proceed with the replacement and reassembly.
Step-by-step replacement
Follow these instructions to replace the cabin air filter.
- Turn off the engine and HVAC system. Open the glove box on the passenger side.
- Gently squeeze the sides of the glove box to release the stops and lower the box down to access the area behind it.
- Locate the rectangular cabin air filter housing behind the glove box; remove the cover by either squeezing the tabs or unsnapping the clips.
- Take out the old filter and check the orientation. Note the airflow arrows on the filter.
- Insert the new filter with the arrows pointing toward the HVAC unit (usually downward into the housing).
- Reattach the filter cover, ensuring it clicks or tabs are secured.
- Raise the glove box back into place and push in the stops so it is secure.
- Start the vehicle and run the HVAC on fresh air to verify proper airflow and that the filter is seating correctly.
After completing the steps, your cabin air system should operate normally, with improved airflow and filtration.
Variations and verification
Not every 2009 GMC Sierra configuration includes a cabin air filter. Some base or region-specific models may omit it. If you cannot locate a filter housing behind the glove box, consult the owner’s manual, check the glove box area for a housing, or contact a dealer with your VIN to confirm whether your truck uses a cabin air filter.
How to confirm for your specific vehicle
To verify, consult the factory service manual or a parts lookup by VIN. If there is a filter, you’ll see a rectangular plastic housing behind the glove box with a removable panel.
Summary
For most 2009 GMC Sierra pickups, the cabin air filter lives behind the passenger-side glove box inside a rectangular housing. Access it by dropping the glove box, remove the panel, replace the filter with the arrows pointing toward the HVAC unit, and reassemble. If you don’t find a housing, your model may not include a cabin air filter—verify with the manual or dealer.