Open the key fob by prying the two halves apart

Most Subaru key fobs split into two plastic halves held together by a small slot. Look for a thin seam running around the edge of the fob—this is where the two halves meet. Insert a flat tool (a coin, flathead screwdriver, or plastic pry tool) into the seam and gently twist to separate them. You do not need force; if you are straining, you are likely in the wrong spot.

Once you have located the correct seam, work your way around the edge, explore gentle pressure at multiple points rather than forcing one spot. The two halves will eventually pop apart. Set the metal spring and any small plastic pieces aside in a safe place—you will need them when reassembling.

Key Takeaways

  • Subaru key fobs use a CR2032 battery, which you can find at any drugstore, grocery store, or hardware store for a few dollars.
  • The battery slides out of a small metal holder inside the fob; note which side faces up before you remove it.
  • The entire process takes about two minutes and requires only a flat tool and a replacement battery.
  • If your fob still does not work after installing a new battery, the problem is likely the fob itself, not the battery.

Identify and remove the old CR2032 battery

Inside the fob you will see a small metal holder with a coin-shaped battery sitting in it. This is a CR2032 battery, the standard size for Subaru key fobs across most model years. Before you remove it, note which side is facing up—the positive side (marked with a + symbol) or the negative side (blank). This matters when you install the new one.

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. Once the old battery is out, set it aside. If the battery is cracked, leaking, or visibly corroded, that explains why your fob stopped working.

Install the new CR2032 battery with the correct orientation

Take your new CR2032 battery and insert it into the metal holder with the same side facing up as the old one. If the positive side was up before, the positive side goes up now. Slide it in gently until it sits flat in the holder. You should hear or feel a small click as it seats properly.

If the battery does not sit flat or feels loose, remove it and check that you have the right orientation. A CR2032 will only fit one way if you are paying attention to which side goes where. Do not force it.

Reassemble the key fob halves

Before you close the fob, make sure the metal spring and any plastic pieces you removed are back in place inside one of the halves. These small parts are straightforward to lose and essential for the fob to work. Line up the two halves so the seam is even all the way around, then press them together firmly until you hear a click.

Work your way around the edge, pressing gently to may support both halves are seated evenly. The fob should feel solid when you are done, not loose or wobbly. If it feels off, pop it open again and check that nothing is caught between the halves.

Test the key fob to confirm it works

Stand near your Subaru and press each button on the fob—lock, unlock, panic, and trunk release if your model has one. You should see the lights on your car respond, and you should hear the locks engage or disengage. If nothing happens, try pressing the buttons several more times; sometimes a new battery needs a moment to make full contact.

If the fob still does not work after a few attempts, the problem is likely inside the fob itself—a broken button contact, corroded circuit board, or damaged internal components. A new battery will not fix those issues, and you will need to replace the fob rather than repair it.

Where to buy a CR2032 battery

CR2032 batteries are inexpensive and widely available. You can find them at drugstores (CVS, Walgreens), grocery stores, hardware stores (Home Depot, Lowe's), and online retailers. A single battery usually costs between two and five dollars. Many stores sell them in multipacks if you want spares for other devices—remote controls, calculators, and some watches also use CR2032 batteries.

If you are unsure whether you have the right battery, check the number printed on the old one before you throw it away, or bring the old battery to the store and compare it to the replacement. The number CR2032 will be clearly marked on the packaging.

When to call a dealer or locksmith

If you have replaced the battery and the fob still does not work, the problem is inside the fob housing. Subaru dealers can reprogram or replace key fobs, though this is more expensive than a battery replacement. A locksmith who works with car keys can often do the same thing for less money.

If your fob is physically damaged—cracked, water-damaged, or the buttons are stuck—replacement is your only option. Do not attempt to repair internal damage yourself; the circuits and contacts are too small and fragile to work with at home.

Frequently Asked Questions

How often do I need to change the battery in my Subaru key fob?

A CR2032 battery typically lasts three to four years with normal use, though this varies depending on how often you use the fob. If you use it multiple times per day, the battery may wear out sooner. You will notice the fob becoming less responsive before it stops working entirely—buttons may require multiple presses or only work from very close range.

Can I use a different battery size if I cannot find a CR2032?

No. The CR2032 is the correct size for Subaru key fobs, and other battery sizes will not fit the holder properly or will not provide the correct voltage. Stick with CR2032. They are inexpensive and straightforward to find, so there is no reason to substitute.

What if I lose one of the small metal pieces inside the fob when I open it?

The metal spring is essential for the fob to work. If you lose it, you will need to order a replacement spring from a Subaru dealer or find a compatible part online. The fob will not function without it. To avoid this, work over a clean, flat surface and keep all small pieces in a small container while you work.

Is it safe to handle a CR2032 battery with my bare hands?

Yes, CR2032 batteries are safe to handle with bare hands. They are not toxic and do not pose a shock hazard. Wash your hands afterward if you prefer, but there is no danger from touching the battery itself. Do not swallow it or let children play with it unsupervised.

Why does my new battery not work right away?

Sometimes a new battery needs a moment to make full electrical contact with the holder. Press the buttons several times in succession to help the battery settle. If it still does not work after ten to fifteen button presses, the problem is likely the fob itself, not the battery.