How to Replace the Key Fob Battery in a Cadillac CELESTIQ

1. Press the button on the side of the remote key near the bottom and pull out the mechanical key.
2. Use the mechanical key blade in the slot to remove the battery cover by hand.
3. Pull the tab to lift the seal and reach the battery.
4. Remove the old battery without using a metal object.
5. Insert the 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 onto the remote key.
8. Reinsert the mechanical key.

• Replace the battery when the DIC displays REPLACE BATTERY IN KEY.
• Do not touch the circuitry on the remote key, as static can damage it.
• If the key is not resealed properly, liquids could enter and damage it.

Source: 2026 Cadillac CELESTIQ owner's manual, PDF pages 12, 13. 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.