2010 Subaru Legacy Key Replacement

2010 Legacy key specs

From 2010 to 2012 the Legacy uses a four-button remote-head key with a high-security DAT17 blade, so it needs a laser-cutting machine rather than an edge cutter. Every car in these years starts with a turn key, and the transponder and remote ride together in the key head. Subaru's bulletin lists the 2010 key as part 57497AJ00A and the 2011-2012 key as AJ10A, a reminder to match the part number before you order a replacement online.

What's specific to the 2010 Legacy

2010 was the first model year of the Legacy BM (fifth generation). Early-production cars sometimes use different part numbers than later ones, so for a 2010 Subaru Legacy we confirm the exact key from the VIN or the old key's FCC ID before cutting anything. It also marks a change from the previous generation: the 2009 Legacy used a basic mechanical key, a transponder (chip) key, a key with a separate remote fob and a remote head key, while the 2010 uses a remote head key. Keys from the older car will not work in this one.

A 2010 Subaru Legacy is about 16 years old. Original keys are often worn smooth, and some factory remotes for cars this age are discontinued, so we may suggest a quality aftermarket remote or a separate fob. Because older immobilizers are simpler, all-keys-lost jobs on cars this age are usually more straightforward than on late models.

Key options for the 2010 Subaru Legacy

• Remote head key. A remote-head key puts two separate systems in one piece: a cut blade with a transponder chip that the immobilizer reads, and a small circuit board with buttons that signals the body control module to work the door locks. On a 2010 Subaru Legacy with this style of key, each side is programmed separately. That explains some confusing failures. If the remote stops working but the car still starts, the problem is usually the battery or the remote board. If the buttons work but the engine won't run, look at the chip side. Knowing which half failed tells us whether you need a repair, a reprogram or a whole new key.

How the Subaru immobilizer works on the Legacy

Subaru came to engine immobilizers later than most brands sold in the US, which keeps things simple for owners of early-2000s models: no 2000-2004 US Subaru has a transponder, so a correctly cut key starts the car. Subaru's own chart shows immobilizers arriving by model and trim from the 2005 model year. That year only the Forester XT, Impreza STi, Legacy GT and Outback XT and 3.0R had one. Every Legacy, Outback and Tribeca followed for 2006, the WRX joined the STi, the whole Impreza line had one by 2008 and the whole Forester line by 2009. The first systems use Texas 4D62 chips in side-cut keys. Subaru then moved to high-security laser-cut keys on 2008-2011 Imprezas, 2008-2014 WRX and STI models, 2009-2013 Foresters and 2010-2014 Legacy and Outback models. From the 2012 Impreza, an 80-bit Subaru G chip arrived in a side-cut remote-head key. The 2017 Impreza introduced the 128-bit Subaru H chip, which reached the Crosstrek for 2018, the Forester and Ascent for 2019 and the Legacy and Outback for 2020. Keyless Access smart keys began with the 2013 BRZ and the 2013-2014 Legacy and Outback.

• Subaru's bulletin describes the 2010-2014 Legacy key as a high-security key with immobilizer and keyless entry.
• The 2010 remote-head key, part 57497AJ00A, uses FCC ID CWTWBU766 at 433.92 MHz; the 2011 and later key, AJ10A, uses CWTWB1U811 at 315 MHz.

Programming a 2010 Legacy key

We cut the DAT17 blade on a high-security machine from your key code or by decoding the driver's door lock, then program the transponder through the OBD-II port, with the remote buttons registered in the same session. Subaru's professional lock-information service supplies the data tied to your VIN, so a spare and an all-keys-lost job follow the same steps. Suppliers list both 4D62 and 4D60-labeled chips for these keys, so we identify the chip before choosing a blank.

Lost every key to your Legacy?

1. Gather your documents and the VIN. Call with the year, make, model and VIN if you can read it through the windshield, plus where the car is parked. Those details let us confirm whether your Subaru Legacy can be done on-site and bring the right key, so the first trip is the only trip.
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. A lost key's metal blade can still open your doors even after its chip is erased. If the keys disappeared along with something showing where you live or park, consider rekeying the car's door lock cylinders too. We'll also recommend leaving with two working keys, not one.

Why a spare key pays for itself

• 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.
• 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.
• A spare stored safely at home rescues you from a locked car with the fob sitting on the seat, a key dropped somewhere along a hiking trail, or a fob that stops responding on a busy morning. Keep it indoors, never in a magnetic box under the bumper.

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 Legacy and your schedule.

Legacy key battery

If a new CR1620 doesn't bring the fob back, the battery wasn't the problem. Common culprits include a battery holder whose solder joints have cracked from drops, contacts corroded by moisture, worn rubber button pads that no longer reach the circuit, or a board damaged by water. We can test whether the fob is transmitting at all and inspect the board closely. Sometimes a new shell or a resoldered holder solves it; sometimes the fob has to be replaced and programmed. Meanwhile, the car can usually still be started with the fob held at the backup spot described in the owner's manual.

How the job works

1. Identify the exact key your Legacy 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. California holds licensed locksmiths responsible for knowing whose car they're making keys for. We record your name, the VIN and the plate on a work order. If you aren't the registered owner, you'll need the owner's written authorization along with your own photo ID before we begin.
3. Get the key code or decode the lock. If you still have a working key, we can read its cuts directly and check them against the factory depths for the Subaru keyway. A worn key gets corrected back to spec during this step, so the new key turns crisply instead of reproducing years of wear in a fresh piece of metal.
4. Cut the blade on-site. Cutting happens right beside your car. For a smart key, that means the emergency blade hidden inside the fob; for a transponder or remote-head key, it's the main blade you'll use every day. We deburr the cuts and check the fit in each lock so nothing binds or sticks later on.
5. Program the chip, remote or smart key. With the blade done, we connect to the OBD-II port and register the new key with the immobilizer. Depending on the Subaru system, this may involve a security PIN, a timed waiting period, or on-board button sequences for the remote. On some vehicles we clone a working key's chip instead, when that's the more reliable path.
6. Test everything and clear out old keys. The last step is a short walkthrough. We show you how many keys the car now recognizes, point out the dead-fob start method for your vehicle, and hand you an itemized receipt. If a spare makes sense, it's simplest to add it during this same visit while the equipment is already connected.

What affects the price of a Legacy 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 Legacy 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.
• All keys lost or adding a key. Adding a key while a working one is in hand is the simpler job. With every key gone, we may have to open the car, decode a lock to originate the cuts, and run a longer programming routine, so all-keys-lost work takes more time and costs more.
• Travel, timing and extra repairs. Sometimes a key problem is really a lock problem: an ignition that won't turn even with the right key, or a door cylinder that has been jammed for years. Fixing those is separate work. We point them out, explain the options, and quote the whole job up front so the bill holds no surprises.

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

• Between 2005 and 2008 Subaru fitted immobilizers by trim, so a base Forester or Impreza of those years may have no chip while the turbocharged version does. Check before buying blanks, because a chipless copy won't start an XT, WRX or STi.
• If a Keyless Access fob battery dies, the car can usually still be started with the backup method in the owner's manual, which uses the fob and the start button. The emergency blade hidden in the fob opens the driver's door.
• 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.

Tips from a mobile locksmith

• If your vehicle has a proximity key, think about where it sleeps at night. A fob hanging by the front door can sit within range of relay equipment used to open and start cars from outside. A drawer deeper inside the house, a signal-blocking pouch, or the fob's own sleep mode reduces that risk considerably.
• Photograph the back of your fob and any key tag that came with the car. The FCC ID, part number and key code printed there make ordering a replacement faster and more accurate. Store the photos somewhere you can reach from any device, not only on the phone that might go missing along with the keys.
• 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

Making car keys is regulated work in California. Locksmiths are licensed and overseen by the Bureau of Security and Investigative Services under the Locksmith Act, Business and Professions Code section 6980 and following, and Julian's Locksmith holds company license LCO7891. Verification protects you more than anyone: a locksmith who will make a key for whoever asks will also make one for someone who wants your car. We record your name, the vehicle and its VIN on a work order, and we politely decline jobs where ownership can't be established. You can look up our license at search.dca.ca.gov.

Need a 2010 Subaru Legacy key?

The quickest route to a working key for a 2010 Subaru Legacy starts with a short phone call. Dial (951) 903-3193, share the VIN and where the car is parked in Southern California, and we'll tell you whether it's an on-site job, a dealer job, or a mix of both. No pressure and no surprise charges, just a straight plan.