Chevrolet Sonic key fob battery

Flip key

1. Fold the blade out so it is out of the way, or keep it folded if your case opens from the side; the battery sits in the plastic body, not the blade.
2. Find the seam or small slot on the body (often at the end away from the blade) and twist a coin or small flat screwdriver in it until the cover lifts.
3. Take out the old cell, noting which side faced you, and fit the new one the same way.
4. Clip the body closed, fold the blade, and test the buttons from a few steps away.

A CR2032 is 20 mm across and 3.2 mm thick. CR2032, CR2025 and CR2016 share the same width but not the same thickness, so a swap between them can leave a loose contact or a case that will not close.

Smart key (push-button start)

1. Most push-button fobs hide a metal backup key. Press or slide its catch and draw the key out first.
2. Use the slot where the metal key sat. Twist, do not lever hard, and work along the seam until the halves separate.
3. Note which side of the old coin cell faces up (usually the side with the writing), lift it out with a plastic tool, and press the new one in the same way.
4. Snap the halves back together, slide the metal key home, and press each button, then try the start button from the driver's seat.

On many recent GM smart remotes a button on the side releases the key; the slot at the bottom is where the case opens.

A CR2032 is 20 mm across and 3.2 mm thick. CR2032, CR2025 and CR2016 share the same width but not the same thickness, so a swap between them can leave a loose contact or a case that will not close.