Subaru Key Fob Battery Replacement: Every Fob Generation, Step by Step

A Subaru key fob that stops locking or unlocking the doors from a few feet away is almost always a battery problem, not a fob problem. The tricky part is that Subaru has used several different fob designs over the years, and each one opens differently and takes a different battery. Guessing wrong can crack a case or leave you reassembling a fob with the battery in backwards. This guide walks through each Subaru fob generation so you can identify what you're holding, open it correctly, and get it back together the first time.

Subaru Key Fob Generations at a Glance

Treat the table as a starting point, not a guarantee — Subaru changed fob electronics partway through some model years, and the battery type is always printed on the old cell itself. Read it before you order a replacement.

Older Remote-Head Key (Blade and Buttons in One Piece)

This is the style where the metal key blade and the remote buttons are molded into a single head — common on older Legacy, Outback, Forester and Impreza models. Two variations show up in the field:

• A small Phillips or Torx screw on the back of the fob head, which separates the case halves once removed.
• No visible screw, meaning the case is held by internal clips and needs to be split at the seam with a thin plastic spudger or flat screwdriver, working around the edge rather than prying at one point.

Once open, the battery sits in a plastic holder or directly against the circuit board contacts. These almost always take a CR2032, but double-check the printing on the old cell before ordering — a small number of older units used a CR1620. Note the polarity (which face is up) before removing the old battery, since the holder often looks the same either way.

2015-ish 3- or 4-Button Remote Fob (No Push-to-Start)

This is the standalone plastic remote — no blade built in — used alongside a separate metal key on many Impreza, Legacy, Outback and Forester trims that don't have push-button start. These typically split apart at a seam running around the case, usually starting at a small notch near the key ring loop. Insert a flat tool into the notch and work it around the perimeter gently; these cases are more likely to crack if you pry hard from one spot instead of walking the tool around.

Battery is almost always a CR2032 in this style. The battery tray usually pops out as one piece, making it easy to see the plus-side orientation before you swap cells.

Push-to-Start Smart Key (Keyless Access)

This is the fob for vehicles with a push-button start and proximity entry — most current Outback, Forester, Crosstrek, Legacy and Impreza trims fall here. The case does not split at an obvious seam on the outside because the mechanical emergency blade covers the access point:

1. Find the small release button or slider on the back of the fob (often labeled or recessed) and slide the metal emergency blade out.
2. The slot the blade sat in exposes a seam or small opening — insert a flat tool there and gently separate the case.
3. Once open, the battery is usually a CR2032, held either in a tray or directly under a small retaining clip.

Smart keys are more sensitive to reassembly than older remotes: make sure the battery is seated flat with the correct polarity and that the case snaps fully closed on all sides before testing, since a partially closed case can cause an intermittent connection rather than a clean dead-fob symptom.

Which Battery Does a Subaru Key Fob Take?

Across nearly every Subaru fob style from the last two decades, the answer is CR2032. The exceptions are a handful of older remote-head keys that use a CR1620, so the safest step is always to read the printing on the battery you're removing rather than assuming from the model year alone. Buying a small multi-pack of CR2032 cells is reasonable if you're servicing more than one Subaru, since it's by far the most common fit.

The Fob Still Doesn't Work After a New Battery

If the fob is unresponsive, weak, or intermittent after a fresh battery, the cause is usually one of these, roughly in order of likelihood:

• Battery seated wrong or case not fully closed — reopen it, confirm polarity, and press every edge of the case closed before testing again.
• Corroded or dirty contacts — a battery that sat dead for a long time can leave residue on the contact points; a gentle wipe often restores connection.
• The internal signal has drifted out of sync with the vehicle — this shows up as a fob that clicks and lights up but doesn't lock or unlock the doors, and it usually needs a resync procedure rather than another battery.
• A failed transponder or transmitter — less common, but if resync doesn't help, the fob's electronics themselves may need replacement rather than repair.

Before ordering a replacement fob, confirm the FCC ID printed on the back of your current fob so whatever you order is guaranteed to match — see our guide on finding the FCC ID on a key fob. And if you do end up with a new fob in hand, our key fob programming guide walks through what onboard programming can and can't do versus a tool-based session.

FAQ

What battery does a Subaru key fob take? Most Subaru fobs from the last two decades use a CR2032 coin cell. A small number of older remote-head keys use a CR1620 instead, so check the printing on the battery you remove before buying a replacement.

How do I know if my Subaru key fob battery is low? The most common sign is reduced range — the fob only locks or unlocks the doors when you're standing right next to the vehicle instead of from several feet away. Some Subaru dashboards also show a low-key-battery warning message.

Can I replace a Subaru key fob battery myself, or do I need a locksmith? Battery replacement is a DIY job on every Subaru fob style — no programming is needed for a simple battery swap. A locksmith becomes necessary if the fob doesn't work after a new battery (which usually points to a resync or a failed fob) or if you need a replacement fob cut and programmed from scratch.

Why won't my Subaru fob lock the doors even though the buttons light up or click? That symptom usually means the battery is fine but the fob's remote signal isn't reaching the vehicle's receiver, or the signal has drifted out of sync. It's a different problem from a dead battery and generally requires a resync rather than another battery swap.

If you're a locksmith who needs a Subaru replacement fob rather than just a battery, Car Key Source stocks exact-fit aftermarket fobs matched by FCC ID and part number, not guesswork. Browse proximity and smart key fobs or look up the exact fob for a vehicle, and apply for a trade account to see wholesale pricing.