How to Replace the Key Fob Battery in a Chevrolet Trailblazer

1. Press the button on the bottom of the remote key and remove the key; never pull it out without pressing the button.
2. Insert a flat, thin object and remove the back cover.
3. Lift the old battery out with a flat object and remove it.
4. Insert the new battery with the positive side toward the back cover, using a CR2032 or equivalent.
5. Check that the silicone mat sits correctly with no gaps or wrinkles.
6. Set the remote key button side down on a hard surface and press the other half straight down to close it.
7. Insert the key back into the remote key.

• Replace the battery soon when the DIC displays REPLACE BATTERY IN REMOTE KEY.
• Do not touch the circuitry on the remote key, since static can damage it.

Source: 2026 Chevrolet Trailblazer 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.