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Subaru key fob battery dead? Here’s how to replace it

ByGreedy Wheels

You can swap the battery in most Subaru key fobs in under five minutes using a coin or a small flathead screwdriver. The exact steps depend on whether you have a standard remote fob (separate physical key) or a push‑to‑start smart key fob. Before you crack open the fob, take thirty seconds to confirm which battery type you need and gather the right tools – that saves the most common headache: prying the wrong seam or forcing in a battery that doesn’t fit.

Which Battery Does Your Subaru Fob Need?

Most Subaru key fobs from the mid‑2000s onward use a CR2032 lithium coin cell (3V). However, a few older styles differ:

  • Standard remote fobs (2005–2015 era) – often include a separate metal key and typically use a CR2032. Some early flip‑key remotes (e.g., 2003–2006 Impreza) may use a CR1620 or CR2025.
  • Smart key fobs (2015+ Legacy, Outback, Forester, 2016+ WRX/STI) – almost exclusively CR2032. The 2020+ Outback/Legacy with the larger, rectangular fob also takes a CR2032.
  • Fob with a loop (e.g., 2008–2012 Tribeca) – also CR2032.

The safest way to confirm is to open the fob and read the number printed on the existing battery. If you can’t get it open without a reference, check your owner’s manual under “Keyless Access” or call a Subaru parts counter with your VIN. A CR2032 is the most common replacement, but a slightly thinner CR2025 (3V) will work in most CR2032 slots – it just won’t last as long (about six months instead of two years). Avoid forcing a thicker CR2032 into a fob designed for a CR1620 – that can crack the casing and ruin the fob permanently.

Battery freshness matters. Even a new CR2032 can be weak if it sat on a shelf for years. Buy from a store with steady turnover (grocery store, pharmacy, or auto‑parts store) and check the expiration date on the package. A battery marked for 2030 is fine; one marked for 2019 is likely near dead.

Quick Prep Checklist

  • [ ] Confirm the battery number (CR2032, CR2025, or CR1620) from the old battery or manual.
  • [ ] Have a fresh battery of the correct type on hand.
  • [ ] A small flathead screwdriver or a dime (for some fob slots) or a plastic spudger (safer for smart fobs).
  • [ ] A clean, well‑lit work surface – avoid doing this over carpet or in direct sun where you could lose small parts.
  • [ ] Your Subaru nearby so you can test the fob immediately after reassembly.

Two Subaru Fob Types – Find Yours

Type A: Standard Remote Fob (Separate Physical Key)

This is the older style with a rectangular fob and a detachable metal key blade. It’s found on most Subarus built before about 2015 (except Impreza models that had push‑to‑start earlier). The battery compartment is on the back, accessed by splitting the fob along a side seam.

Step 1

Locate the small notch or slot on the side of the fob. On most Subaru fobs it’s near the top edge. Insert a coin (dime works well) or a small flathead screwdriver and twist gently to separate the two halves. You’ll hear a click as the clips release.

Step 2

Lift the back cover off. You’ll now see the battery resting in a metal clip. Note which side faces up – usually the “+” side is visible, but some fobs have the marking on the clip itself. If you’re not sure, snap a phone photo before removing.

Step 3

Use your fingernail or the screwdriver tip to pry the battery out. If the battery is stuck, gently slide a thin tool under it from one edge. Do not use excessive force – you could bend the contact clip.

Step 4

Insert the new battery with the same “+” orientation. Press it firmly into the clip until it clicks. Ensure it sits flat and does not rock.

Step 5

Align the two halves of the fob and press together until they snap shut. Run your finger along the seam to confirm it’s flush all around. If the seam is not flush, you probably bent a clip – gently pry apart and try again.

Checkpoint

Before you walk away from your work surface, press any button – the LED on the fob should flash. If it doesn’t, flip the battery and try again. If still dead, the battery may be defective – try a different one. If the LED flashes but the doors don’t respond, proceed to the Success Check section.

Type B: Smart Key Fob (Push‑to‑Start)

This one‑piece fob has no visible screws. It’s used on 2015+ Legacy/Outback, 2019+ Forester, 2016+ WRX/STI, 2020+ Outback/Legacy, and most newer Subarus. It includes a hidden mechanical key tucked inside.

Step 1

Locate the release tab on the side or bottom of the fob. Slide or press it to release the hidden mechanical key. Pull the key out completely. On some fobs (e.g., 2020 Outback) the release is a small button on the back near the bottom.

Step 2

You’ll see a slot where the key was. Insert the key tip or a flathead screwdriver into that slot and gently twist to separate the two halves of the fob. Some smart fobs also have a small notch on the outside edge – you can use a coin there if it’s easier. Work slowly; the plastic clips can break if you force them.

Step 3

The internal circuit board and battery are now exposed. Carefully lift the battery out with your fingertip or a plastic spudger. Note the orientation – CR2032 batteries always sit with the “+” side up in Subaru smart fobs. The contacts are springy; do not lose the small metal spring that holds the battery down.

Step 4

Place the new battery in the same orientation. Press down until it’s seated. If the spring contact seems bent, gently bend it back so it makes solid contact with the battery top.

Step 5

Snap the fob halves back together. Start with the top edge, then press down until you hear clicks. Reinsert the mechanical key until it clicks into place.

Checkpoint

After reassembly, walk to your Subaru and see if the car recognizes the fob: doors should unlock when you touch the handle (or press a button), and you should be able to push‑to‑start. If not, open the fob again and verify the battery is fully seated and oriented correctly. Also check that the metal contact tabs haven’t bent out of shape – a common cause of intermittent operation. If the fob works for a few days then stops, bent contacts are likely the culprit.

Where People Usually Get Stuck

  • Prying the wrong seam. On Type A fobs, the seam runs around the edge. If you try to pry the back cover off from the top, you may break the internal clips. Always start at the notch indicated on the fob.
  • Using a metal screwdriver on a smart fob. The circuit board is very close to the edge. A plastic spudger or your fingernail is safer. If you must use metal, angle it away from the board and never pry directly on a component.
  • Inserting the battery upside down. The fob won’t work, and in rare cases a reversed battery can short the board. Always note the “+” orientation before removing the old battery. If you already removed it without noting, check your phone photo or look for a small “+” icon molded into the plastic near the battery cavity.
  • Corroded contacts. If the old battery leaked or the fob got wet, the metal contacts may have white crust or green corrosion. Clean them gently with a dry toothbrush or a pencil eraser. If the corrosion is heavy, the fob may be damaged – you can try replacing the contact springs (available online for about $5), but often the circuit board is ruined.
  • Not testing before reassembly. Always press a button while the fob is still open (Type A) or before closing the smart fob. If the LED doesn’t flash, you can correct orientation immediately without having to pry it open again.

When to Stop DIY and Go to the Dealer

If your fob still won’t work after:

  • Confirming the battery is fresh and correctly oriented
  • Cleaning the contacts
  • Trying a second new battery (to rule out a dud)
  • Snap‑testing the fob LED (no flash = dead fob)

…then the issue is likely not the battery. Possible causes:

1. Damaged circuit board – water intrusion, physical drop, or age. A replacement smart fob from the dealer costs roughly $150–$400 depending on model and programming. Used fobs from online sellers often cannot be re‑programmed to your car – stick with an OEM part or a reputable locksmith that can handle Subaru immobilizers.

2. Needs re‑programming – Some Subaru models allow DIY reprogramming by hopping in the car and following a sequence (insert key, turn to on, press a button, etc.). Check your owner’s manual or online forums for your specific year and trim. Many 2015+ Subarus with push‑to‑start require a dealer scan tool to pair a new fob.

3. Car’s receiver module failed – Rare, but possible if other key fobs also stop working. A dealer can diagnose this with a security system test.

Stop point: If the fob LED doesn’t flash when you press a button after a fresh battery, the fob itself is most likely dead. At that point, you’re better off buying a replacement than chasing further electrical investigation.

Success Check – Did It Work?

After the battery is installed and the fob is closed, stand within a few feet of your Subaru and press the lock/unlock button. The LED on the fob should flash, and the doors should respond. For smart keys, touch the door handle (with the fob in your pocket) – the car should lock/unlock, and you should be able to start the engine with the push button.

If the LED lights up but the doors don’t respond, the fob may need to be re‑synced. Try starting the car normally: on many Subaru models (especially 2015+), inserting the fob into the slot or holding it near the push button while starting will automatically re‑sync. If nothing happens after that, or if the LED is dark, go back to the Where People Get Stuck section and verify contacts and battery orientation.

Replacing your Subaru key fob battery is a simple DIY task that costs a couple of dollars and saves a dealer trip – but knowing when to stop and get help keeps you from wasting time on a lost cause.

Frequently Asked Questions

Q: Can I use a CR2025 instead of a CR2032 in my Subaru fob?

Yes, a CR2025 is the same voltage and diameter but half the thickness. It will work in most fobs designed for a CR2032, but its shorter lifespan (6–8 months vs. 2 years) means you’ll replace it sooner. It may also rattle slightly in the compartment.

Q: My fob works intermittently – is it the battery or something else?

Intermittent operation often points to a loose contact, not a dying battery. Open the fob and check that the metal prongs gripping the battery haven’t spread apart. Gently bend

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