Opening your Subaru key fob takes about two minutes and requires only a coin or flat tool
Most Subaru key fobs open by inserting a flat object—a coin, flathead screwdriver, or the small metal key that slides out from the fob itself—into the seam running around the edge. You rotate or pry gently until the two plastic halves separate. The battery sits in a small metal holder inside. Once you know where the seam is, the whole process takes less time than finding where you put the fob down.
The exact method depends on which generation of Subaru fob you have, but the basic principle is the same across models from the last 15 years. If you have an older fob or a newer push-button model, the opening method may differ slightly, but the steps below cover the most common versions you will encounter.
Key Takeaways
- The seam runs horizontally around the middle of most Subaru fobs, and you insert a coin or flat tool into it to separate the two halves.
- Turn the coin or tool gently—do not force it, as the plastic cracks easily and replacement fobs cost $150 to $400 depending on your model year.
- The battery type varies by model; check your owner's manual or the old battery itself to confirm whether you need CR2032, CR2025, or another size.
- Battery contacts inside the fob can corrode or become loose, so clean them lightly with a dry cloth before inserting a new battery.
- If the fob still does not work after replacing the battery, the problem is usually a dead battery in the car's receiver or a programming issue, not the fob itself.
Locating the seam and preparing your tools
Hold the fob in your hand with the buttons facing you. Look for a thin horizontal line running around the middle of the fob—this is the seam where the two plastic halves meet. On some models, you may see a small notch or indent on one side of this seam; that is where the manufacturer intended you to insert your tool.
Gather a coin (a dime or penny works well) or a small flathead screwdriver. Some Subaru fobs include a small metal key that slides out from the bottom; this key can also serve as your opening tool. Avoid using anything sharp or pointed that could scratch the plastic or damage the electronics inside. A butter knife or old credit card can work in a pinch, though a coin gives you better control.
Separating the two halves
Insert your coin or tool into the seam, starting at the notch if you can see one. explore steady, gentle pressure—think of it as coaxing the fob open rather than forcing it. You should feel the two halves begin to separate after a few seconds of pressure. If nothing happens after 10 to 15 seconds of gentle effort, try a different spot along the seam or rotate the fob to see if there is a better entry point.
Once you feel movement, work your way around the seam, inserting the tool at different points and gently prying. The halves will eventually pop apart. Do not twist or bend the fob itself—let the tool do the work. If you force it, you risk cracking the plastic housing, which means buying a replacement fob rather than just a battery.
Identifying and removing the old battery
Inside the fob, you will see a small metal battery holder with a round battery sitting in it. The battery is usually held in place by a small metal clip or spring. Note which side of the battery is facing up—the flat side or the raised side—because you will need to insert the new battery the same way.
Gently lift or slide the battery out of its holder. If it is stuck, use your fingernail or a plastic tool to nudge it free. Do not use metal tools inside the fob, as you could accidentally short the electronics. Once the battery is out, look at the top to find the battery type printed on it—usually CR2032, CR2025, or CR2016. Write this down or take a photo so you know exactly what to buy.
Cleaning the battery contacts
Before you insert a new battery, take a moment to inspect the metal contacts inside the battery holder. Over time, these contacts can develop a thin layer of corrosion or dirt that prevents the battery from making good contact. Use a dry cloth or a pencil eraser to gently rub the contacts clean. Do not use water or any liquid, as moisture can damage the circuit board.
If the contacts look heavily corroded—dark or discolored—you can use a small amount of rubbing alcohol on a cotton swab to clean them, but let everything dry completely before inserting the new battery. This step takes 30 seconds and often solves problems where a new battery does not seem to work at first.
Installing the new battery and reassembling the fob
Insert the new battery into the holder with the same side facing up as the old battery was. The battery should sit flat in the holder and make contact with the metal clips or spring on both sides. You should hear or feel a small click as the battery settles into place.
Now align the two halves of the fob and press them together firmly. Start at one end and work your way around, pressing until you hear a click or feel the halves snap together. The seam should be tight and even all the way around. Test the fob by pressing each button—the lights inside should flash, and your car should respond to the lock and unlock buttons.
What to do if the fob still does not work
If you installed a new battery and the fob still does not work, the problem is usually not the fob itself. The most common cause is a dead battery in your car's receiver unit, which sits in the door lock mechanism or under the dashboard. Try using your spare key fob if you have one; if the spare works, your main fob may have a damaged circuit board.
If neither fob works, or if only one button works, the issue is likely in the car, not the fob. Check your car's battery voltage with a multimeter if you have one, or take the car to a Subaru dealer to have the receiver diagnosed. Some newer Subaru models also require the fob to be reprogrammed after a battery replacement; your owner's manual will tell you if yours does, and the process usually involves turning the key in the ignition a specific number of times.
Frequently Asked Questions
What battery type does my Subaru key fob use?
Most Subaru fobs use a CR2032 battery, but some older models use CR2025 or CR2016. The easiest way to find out is to look at the old battery itself—the type is printed on top. You can also check your owner's manual or call your Subaru dealer with your model year and they will tell you when ready.
Can I damage the fob by opening it wrong?
Yes, the plastic cracks easily if you force it or use too much pressure. A replacement fob costs $150 to $400 depending on your model year and whether it has remote start or other features. Take your time, use gentle pressure, and work your way around the seam slowly rather than trying to pry it open in one spot.
How often do I need to replace the battery?
Most Subaru key fob batteries last two to four years, depending on how often you use the fob. If your fob starts to work only when you hold it close to the car, or if buttons stop responding, the battery is probably dying and needs replacement soon.
Do I need to reprogram my fob after changing the battery?
Most Subaru models do not require reprogramming after a straightforward battery change. However, some newer models do. Check your owner's manual for your specific year and model. If reprogramming is needed, the manual will walk you through the steps, which usually involve turning the key in the ignition in a specific pattern.
What if I lost the small metal key that came with my fob?
You do not need it to open the fob. A coin, flathead screwdriver, or butter knife works just as well. The metal key is mainly a backup tool in case you lose your spare fob and need to unlock your car manually, so losing it does not affect your ability to change the battery.