How to Replace the Key Fob Battery in a GMC Sierra Denali 2500HD/3500HD

1. Pry off and remove the back cover of the transmitter with a flat, thin object such as a coin.
2. Press and slide the old battery down toward the pocket in the direction of the key ring, without using a metal object.
3. Remove the battery.
4. Insert a new CR2032 or equivalent battery with the positive side facing up.
5. Make sure the silicone mat sits correctly with no gaps or wrinkles.
6. Set the transmitter button side down on a hard surface and press the other half straight down to close it.

• Replace the battery soon if REPLACE BATTERY IN REMOTE KEY shows on the DIC.
• Do not touch the circuitry in the transmitter, since static can damage it.
• Reassemble carefully so liquids cannot enter the housing.

Source: 2022 GMC Sierra Denali 2500HD/3500HD owner's manual, PDF pages 13, 14. 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.