How to Replace the Key Fob Battery in a GMC Sierra 1500

1. Press the button on the side of the remote key near the bottom and pull out the mechanical key.
2. Put the mechanical key blade in the slot and lift off the battery cover by hand.
3. Remove the battery cover, then pull the tab to peel back the seal over the battery.
4. Take out the old battery without using a metal object.
5. Insert a new CR2450 Lithium or equivalent battery with the positive side facing up.
6. Set the seal back into the groove around the battery compartment.
7. Snap the battery cover back on and reinsert the mechanical key.

• Replace the battery soon when the DIC shows REPLACE BATTERY IN REMOTE KEY.
• Reassemble the key properly so the housing stays sealed against liquids.

Source: 2026 GMC Sierra 1500 owner's manual, PDF pages 20, 21. Steps are summarized in our own words (AI-assisted, checked against the cited pages 2026-10-18). Other model years can differ; your manual has the final word.