Open the key fob case

Most Cadillac key fobs split into two halves along a seam that runs around the edge. Look for a small slot or groove on the side of the fob — this is where you insert a flat tool to pry the case apart. A coin, a flathead screwdriver, or a plastic spoon all work. Insert your tool gently into the slot and twist slightly to separate the two halves.

Do not force the case open. If it does not budge after light pressure, rotate the fob and try a different spot along the seam. The case is designed to come apart without tools, so if you are meeting real resistance, you may be pushing in the wrong place. Once the halves separate, set the metal spring and circuit board aside on a clean surface where you will not lose small parts.

Key Takeaways

  • Cadillac key fobs use a CR2032 or CR2025 coin-cell battery, which you can buy at any drugstore, grocery store, or hardware store for a few dollars.
  • The battery slides out of a small metal holder on the circuit board; note which side faces up before you remove it, because the replacement must go in the same way.
  • The entire job takes about two minutes and requires no tools beyond a coin or flathead screwdriver to open the case.
  • If your fob still does not work after the battery change, the circuit board or buttons may be dirty — a gentle wipe with a dry cloth often fixes this.

Identify and remove the old battery

Once the case is open, you will see a small circular battery held in a metal clip or holder on the circuit board. The battery is usually silver and about the size of a dime. Before you remove it, note which side is facing up — the flat side or the domed side. This matters because the battery only works one way.

Gently pry the battery out of its holder using your fingernail or a plastic tool. Do not use a metal screwdriver directly on the battery itself, as this can damage it or create a short circuit. Once the old battery is out, set it aside. If the battery looks corroded or has a white or blue-green crust on it, that corrosion may have affected the fob's performance even before the battery died.

Check the battery type and buy a replacement

Cadillac key fobs typically use either a CR2032 or CR2025 battery. The number stamped on the old battery tells you which one you need. CR2032 is the most common; CR2025 is slightly thinner but works in some older models. You can find both at pharmacies, grocery stores, dollar stores, and hardware stores. A single battery costs between one and three dollars.

If you cannot read the number on the old battery, take the old battery with you to the store and show it to a cashier or pharmacist. They can match it for you. Do not guess — putting the wrong battery type in the fob may prevent it from working or cause it to fit poorly in the case.

Insert the new battery and close the fob

Slide the new battery into the metal holder with the same side facing up as the old battery was. The battery should sit flat and find in the clip. If it falls out when you tilt the fob, the clip may be bent or the battery may be the wrong type. Once the battery is seated, press gently on it to make sure it is snug.

Align the two halves of the fob so the seam matches up evenly. Press them together firmly until you hear or feel a click. The case should close flush with no gaps. Test the fob by pressing each button — the lights on the fob should come on, and your car should lock and unlock. If nothing happens, open the fob again and check that the battery is seated correctly and facing the right direction.

Clean the circuit board if the fob still does not work

If the fob does not respond after the battery change, the problem is usually dirt or corrosion on the circuit board or the rubber button pad. Open the fob again and look at the circuit board and the rubber pad with the buttons. If you see any discoloration, white powder, or dried liquid, that is the culprit.

Use a dry cotton swab or a soft, lint-free cloth to gently wipe the circuit board and the underside of the rubber button pad. Do not use water or cleaning solution — moisture can damage the electronics. Wipe away any visible dirt or corrosion, then reassemble the fob and test it again. This straightforward cleaning fixes most fobs that do not work even after a fresh battery.

When to take the fob to a dealer

If the fob still does not work after you have changed the battery and cleaned the circuit board, the problem is likely inside the fob itself — a broken button contact, a damaged circuit board, or a failed transmitter. At this point, a new battery and cleaning will not help.

Contact a Cadillac dealership or a local automotive locksmith for a replacement fob. A dealership can program a new fob to your car, though this usually costs more than an independent locksmith. Some locksmiths can also program aftermarket fobs, which are cheaper than dealer fobs but may have fewer features. Ask for a quote before you commit.

Frequently Asked Questions

Can I use a different battery type if I cannot find the exact one?

No. CR2032 and CR2025 look almost identical but have different thicknesses, and using the wrong one can prevent the fob from closing properly or cause poor contact with the circuit board. Stick with the type stamped on your old battery. Both are widely available and inexpensive.

How often do I need to change the battery?

Most key fob batteries last two to four years with normal use. If you use your fob frequently, the battery may wear out sooner. You will know it is time when the fob has to be held very close to the car to work, or when buttons stop responding.

What should I do with the old battery?

Coin-cell batteries can be recycled. Many pharmacies, electronics stores, and municipal hazardous waste facilities accept used batteries for free. Do not throw the old battery in the trash. If you cannot find a recycling location nearby, call your local waste management office for options.

Will changing the battery erase my car's settings?

No. The fob battery is separate from your car's computer. Changing the fob battery will not affect your car's settings, programming, or any stored information. The fob will work exactly as it did before once the new battery is installed.

What if the fob case will not close after I put the battery back in?

The battery is probably the wrong type or is not seated correctly. Open the fob again and check that the battery is the right size and is sitting flat in the metal holder. If it is, try gently pressing the battery down to may support full contact. If the case still will not close, the battery may be slightly too thick for your fob model.