2021 Subaru Crosstrek Key Replacement

2021 Crosstrek key specs

From 2018 the Crosstrek uses the 128-bit H chip. Lower trims generally have a four-button remote-head key with a side-cut blade, while the Limited and other upper trims have Keyless Access with push-button start. Remote-head keys changed from a black internal pod in 2018 to a gray one from 2019. Subaru's bulletin lists the remote-head key as part 57497FL000 for 2018 and SJ051 for 2019 through 2021.

What's specific to the 2021 Crosstrek

The 2021 Subaru Crosstrek is the fourth of 6 model years in the Crosstrek GT (second generation) (2018–2023), so it shares its key system with the rest of that run, which makes replacement parts easy to source. A 2021 Subaru Crosstrek is about 5 years old now. Original fob batteries are near the end of their life at this age, so weak range or a "key not detected" message is often a battery before it is a failed fob. Cars this age are often on their second owner, which is when a single remaining key and a request for a spare tend to show up.

Smart-key cars like the 2021 Crosstrek can be targeted with relay attacks that extend the fob's signal from inside your home, so keep fobs away from exterior walls or in a signal-blocking pouch, and have any missing fob erased from the car.

Key options for the 2021 Subaru Crosstrek

• Remote head key. Remote-head keys look similar across many vehicles, but the electronics inside are not interchangeable. Getting the right one for a Subaru Crosstrek means matching the FCC ID and part number printed on the back or inside the case, the operating frequency, which is commonly 315 MHz on US-market cars, the transponder type, and the button layout. A trim with remote start or a power liftgate may use a four- or five-button version where a base trim uses three. We check those details against your VIN and your existing key, if you have one, before cutting the blade. A wrong match can look perfect and still refuse to program.
• Smart proximity key (push-to-start). Making a new smart key is mostly a programming job. The fob has to match the vehicle's FCC ID, frequency and chip, and then the keyless system must be told to accept it, normally through the OBD-II port. Depending on the platform, that can mean entering a PIN, waiting through a timed security procedure, or on some newer vehicles, using manufacturer online access. When every key is lost, certain models need a module removed and read on the bench. For your Subaru Crosstrek GT (second generation), we'll tell you which of those applies, and if a step is dealer-only, you'll hear it before we drive out. The emergency blade hidden inside the fob is cut by code during the same visit.

How the Subaru immobilizer works on the Crosstrek

• Supplier listings show the black-pod CWTB1G077 remote-head key, part 57497-FL00A, for the 2018 Crosstrek.
• Subaru's bulletin lists Crosstrek remote-head key part 57497SJ051 for 2019 through 2021.
• Smart fobs with FCC ID HYQ14AHK operate at about 434 MHz and are listed for 2017-2020 Subarus, including the Crosstrek.

Programming a 2021 Crosstrek key

Adding a key with one working key present goes through the OBD-II port with current Subaru software. All-keys-lost is more involved: bladed H-chip keys in particular need dedicated Subaru software or an emulator, and some programmers don't support them at all. We look up your VIN and key type first, then tell you whether we can do it on site or whether a dealer visit makes more sense.

Spare keys are routine. All-keys-lost needs specialized Subaru software or emulators; some cars may need the dealer.

Lost every key to your Crosstrek?

With every key gone, the model year decides the job. A 2000-2004 Subaru, a Baja, or a base model built before its line got an immobilizer just needs a key cut by code or by decoding the door lock. On 4D62 cars from 2005 through 2011 and on remote-head cars of the G-chip years, we cut the blade, erase the missing keys and program new ones in one visit. Keyless Access cars of the G-chip years and every H-chip car are harder: some tools need a working key, so we use dedicated Subaru software or an emulator, and a few cars have to go to the dealer. Brand-new platforms, including the 2026 Outback and Subaru's electric models, are usually dealer jobs for now. We tell you plainly which route your car needs and check ID and proof of ownership before any work.

1. Gather your documents and the VIN. Find your registration or title and a government photo ID in the same name. Note the VIN, which is printed on the driver's side of the dashboard and usually on your insurance card. If the paperwork is locked in the car, tell us; we'll open the vehicle first and check it there.
2. Get into the vehicle without damage. Entry comes before key-making because we need access to the ignition, the OBD-II port and sometimes the documents in the glove box. We take care with weather stripping, door frames and paint, and we confirm the dash VIN matches your registration before going any further.
3. Originate a new key from the car. Originating a key means building it without a sample. The door lock usually reveals most of the cuts; any it doesn't are worked out by test-cutting and trying the ignition or a second lock. The finished blade should feel like a factory key, not a forced fit.
4. Program the key to the immobilizer. Next, the new key is introduced to the car's security system. Many vehicles allow this through the OBD-II port with a PIN or security procedure. Some all-keys-lost cases require reading a module on the bench, and a few platforms only allow dealer programming, which we'll tell you up front.
5. Erase missing keys and add a spare. Once the car starts, we remove the lost keys from memory wherever the system allows, so they can't start the engine if someone finds them. Making a second key during the same visit costs much less than a repeat all-keys-lost call down the road.

Why a spare key pays for itself

• Two drivers sharing one key is a daily negotiation. A second key lets a partner, teenager or coworker use the vehicle without handing keys back and forth in parking lots, and it means one person losing their key ring doesn't leave the whole household stuck.
• When you sell or trade in the vehicle, buyers and dealers expect two keys. A missing key can come up during an appraisal or a private-sale negotiation, so having both on hand keeps the conversation about the car, not about what it will cost the next owner to replace one.
• A spare turns a future all-keys-lost emergency into a simple add-a-key job. With one working key in hand, programming is quicker, and the chip or fob can often be paired without decoding locks or reading modules, which keeps the cost of a lost key far lower.

Dealer or mobile locksmith?

Price and parts are the other half of the comparison. Dealers typically sell factory keys only and charge their posted service rates for programming. We offer factory keys where it matters and quality aftermarket alternatives where they perform well, and the quote covers cutting, programming and the trip, with nothing tacked on at the end. Timing differs too. Dealer service departments generally keep business hours, while we take automotive calls every day from 6:30 a.m. to 11:30 p.m., which covers early commutes and late evenings. We're closed overnight, and we'll be upfront if your timing means the dealer or a next-day visit is the better plan. Neither option is wrong; the right one depends on your Crosstrek and your schedule.

Crosstrek key battery

Battery details for the 2021 Crosstrek: CR1620 (remote-head key); CR2032 (smart fob). Swap cells one at a time and match each one exactly; if a key still fails with a fresh battery, the board, buttons or programming may be the problem, which we can test on site.

How the job works

1. Identify the exact key your Crosstrek uses. We ask a few quick questions on the phone: the year, whether the car starts with a turn key or a button, how many keys you have left, and whether the remote still works the doors. Then we check the VIN against our programming references so the van arrives with the correct blank or fob, not a close guess.
2. Verify ownership before any work. Before cutting or programming, we compare your government photo ID with the vehicle registration or title and check that the VIN on the paperwork matches the VIN on the dash. If the registration is locked inside, we open the car first, confirm the documents, and only then make the key.
3. Get the key code or decode the lock. A key is cut from a code, not a guess. When the factory code can be retrieved through manufacturer channels after ownership is verified, we use it. When it can't, we decode a door lock with a pick-decoder tool that reads the wafer positions without damaging anything, then work out any missing cuts.
4. Cut the blade on-site. Our van carries a code-cutting machine that handles both traditional edge-cut blades and the laser-cut, side-milled profiles common on newer keys. The blade is cut to the code, then test-fitted in a door lock and the ignition or emergency keyhole to confirm smooth operation before any programming begins.
5. Program the chip, remote or smart key. Programming tells the car's computers that the new key belongs to the vehicle. Transponder chips are added to the immobilizer, remote buttons to the body control module, and proximity fobs to the keyless system. If a step requires dealer-only access on your Crosstrek, you'll have heard that before we arrived, not halfway through the job.
6. Test everything and clear out old keys. Before we leave, every function gets checked: doors, trunk or liftgate, panic button, remote range, engine start, and the emergency blade in the driver's door. If keys are missing, we delete them from the car's memory where the system allows, so a lost key can no longer start the engine.

What affects the price of a Crosstrek key

• The type of key. The biggest factor is technology. A plain mechanical key is a cutting job only. A transponder key adds a chip and programming. Remote-head and flip keys add a circuit board, and a proximity fob for a push-button Subaru Crosstrek is the most involved of all, both in the part itself and in the programming.
• Factory or aftermarket parts. Factory keys and fobs carry the manufacturer's part number and usually the highest parts cost. Quality aftermarket keys use compatible electronics at a lower price and work well on many vehicles. We tell you which options we trust for your car, and where an aftermarket version has known range or fit issues, we steer you to OEM.
• Programming complexity and security access. Two cars with similar-looking keys can program very differently. Newer platforms often guard key programming behind encrypted access or paid credentials, while older systems allow straightforward OBD-II pairing. We check the exact procedure for your VIN before quoting, so the number reflects the real work involved.
• Blade style and cutting. Traditional edge-cut blades are quick to cut. High-security laser-cut blades, with a groove milled into the side, need a specialized machine and more care, and the blanks themselves cost more. If we have to decode a lock to find the cuts, that adds labor as well.

Call (951) 903-3193 with your VIN and the keys you still have, and we'll quote the job before any work starts.

Common Subaru key problems

• Remote-head keys from 2012 through at least 2022 mostly run on a CR1620 cell, while Keyless Access fobs from 2014 on take a CR2032. The 2024 remote-head key moved to a thicker CR2025. Inland Empire summer heat shortens coin-cell life, and shrinking range is the usual warning.
• Remote-head key shells tend to crack at the blade root after years on a heavy keyring. The remote board and transponder can usually be moved into a new shell with a freshly cut blade, which often costs less than a complete new key.
• Remote-head keys sold under FCC ID CWTB1G077 look alike but differ inside. The 2018-2019 Legacy and Outback versions carry the older G chip, while the 2017-2020 Impreza, Crosstrek, Forester and Ascent versions carry the H chip. Match the part number and pod color, not just the FCC ID.
• Subaru remotes of one era were built on two frequencies under different FCC IDs: CWTWB1U811 at 315 MHz and CWTWBU766 at 433.92 MHz. Both appear on remote-head keys for 2010-2015 Subarus, so match the part number printed on your old key before you buy a replacement.

Tips from a mobile locksmith

• Be careful with discount fobs from online marketplaces. A listing may match your remote's shape while using a different frequency, chip or FCC ID, and many used smart keys are locked to their original vehicle. If you already bought one, send us the listing or a photo before the visit so nobody pays for a programming attempt that can't work.
• Learn your car's dead-fob start method now, in the driveway, rather than in a dark parking lot later. Depending on the make, you hold the fob against the start button or place it in a marked pocket in the console. Also find the hidden keyhole on the driver's door handle and practice using the emergency blade.
• Make the spare before you need it. Adding a key while one still works is quicker and less expensive than starting from nothing, and it keeps the simpler programming options available. Good moments are right after buying the car, or as soon as one of your two keys goes missing.

Proof of ownership

Not every situation fits the simple case, so here's how we handle the common exceptions. For a leased or financed vehicle, a registration that lists you as the registered owner or lessee works with your ID. If you just bought the car, bring the signed title or bill of sale along with your ID. For a company or fleet vehicle, we need written authorization from the business plus the driver's ID. If the car belongs to a family member, the registered owner should be present or provide signed permission and a copy of their ID. Rental vehicles go through the rental company.

Need a 2021 Subaru Crosstrek key?

Don't wait until the last key disappears. If your Subaru Crosstrek is down to one key, or the one you have is falling apart, call (951) 903-3193. We're a licensed California locksmith, license LCO7891, serving Southern California and the rest of the Inland Empire with mobile car key service every day from 6:30 a.m. to 11:30 p.m.